text
stringlengths
49
983k
#include <bits/stdc++.h> using namespace std; const long long M = 1e9 + 7; const long long mod = 998244353; mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count()); long long binpow(long long a, long long b, long long m) { long long res = 1; while (b > 0) { if (b & 1) res = res * a % m; a = a * a % m; b >>= 1; } return res; } long long gcd(long long a, long long b) { return (b == 0 ? a : gcd(b, a % b)); } struct dsu { struct op { int u, l, t; op() {} op(int u, int l, int t) : u(u), l(l), t(t) {} }; vector<int> pai, tam; stack<op> old_pai; stack<op> old_tam; vector<int> g[200200]; dsu() {} dsu(int n) { pai.resize(n); tam = pai; for (int i = 0; i < n; i++) { pai[i] = i; tam[i] = 1; } } vector<int> at, deleted; void init(vector<int> &v) { at.resize(v.size() + 1); deleted.resize(v.size() + 1); for (int i = 0; i < v.size(); i++) { g[i].emplace_back(v[i]); at[v[i]] = i; } } int find(int u) { if (pai[u] == u) return u; return find(pai[u]); } void merge(int u, int v, int t) { int a = find(u); int b = find(v); if (a == b) return; if (tam[a] > tam[b]) swap(a, b); old_pai.emplace(a, pai[a], t); old_tam.emplace(b, tam[b], t); pai[a] = b; tam[b] += tam[a]; for (int &x : g[a]) { g[b].push_back(x); at[x] = b; } } void query(int v) { v = find(v); int go = 0; while (!g[v].empty()) { int u = g[v].back(); g[v].pop_back(); if (u == 0 or at[u] != v or deleted[u]) continue; else { go = u; deleted[u] = 1; break; } } cout << go << "\n"; } void rollback(int t) { while (!old_pai.empty() && old_pai.top().t >= t) { pai[old_pai.top().u] = old_pai.top().l; tam[old_tam.top().u] = old_tam.top().l; for (int &x : g[old_pai.top().l]) { at[x] = old_pai.top().l; } old_pai.pop(); old_tam.pop(); } } }; void solve() { int n, m, q; cin >> n >> m >> q; vector<int> p(n), er(m); { for (auto &_re : p) cin >> _re; }; vector<pair<int, int> > e(m); for (int i = 0; i < m; i++) { cin >> e[i].first >> e[i].second; e[i].first--; e[i].second--; } vector<pair<int, int> > qs(q); for (int i = 0; i < q; i++) { cin >> qs[i].first >> qs[i].second; qs[i].second--; if (qs[i].first == 2) er[qs[i].second] = 1; } dsu D(n); D.init(p); for (int i = 0; i < m; i++) { if (er[i]) continue; D.merge(e[i].first, e[i].second, 0); } int t = 1; for (int i = q - 1; i >= 0; i--) { if (qs[i].first == 2) { D.merge(e[qs[i].second].first, e[qs[i].second].second, t++); } } for (int i = 0; i < n; i++) sort(D.g[i].begin(), D.g[i].end()); for (int i = 0; i < q; i++) { if (qs[i].first == 1) { D.query(qs[i].second); } else { D.rollback(--t); } } } int32_t main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int t = 1; while (t--) { solve(); } }
#include <bits/stdc++.h> void solve(); int main(int argc, char* argv[]) { ::std::ios::sync_with_stdio(false); ::std::cin.tie(0); ::std::cout.tie(0); int tc = 1; while (tc--) solve(); return 0; } using ll = long long; using pii = std::pair<int, int>; using vi = std::vector<int>; using vii = std::vector<pii>; using std::cin; using std::cout; using std::string; using std::vector; const int inf = 0x3f3f3f3f; const int MOD = 998244853; const int N = 500000 + 5; int n, m, q; pii e[N], que[N], t[N * 2]; vi adj[N]; int tin[N], tout[N], timer; int par[N], arr[N]; bool del[N]; int get_father(int x) { if (x != par[x]) par[x] = get_father(par[x]); return par[x]; } void dsu_union(int x, int y) { x = get_father(x); y = get_father(y); if (x == y) return; ++n; par[n] = n; par[x] = n; par[y] = n; adj[n].push_back(x); adj[n].push_back(y); } void dfs(int x) { tin[x] = ++timer; for (int y : adj[x]) dfs(y); tout[x] = timer; } pii segMax(int l, int r) { pii ans(0, 0); ++r; for (l += timer, r += timer; l < r; l /= 2, r /= 2) { if (l & 1) ans = std::max(ans, t[l++]); if (r & 1) ans = std::max(ans, t[--r]); } return ans; } void updatePos(int x, pii value) { x += timer; t[x] = value; while (x > 1) { x /= 2; t[x] = std::max(t[x * 2], t[x * 2 + 1]); } } void solve() { cin >> n >> m >> q; for (int i = 1; i <= n; ++i) cin >> arr[i]; for (int i = 1; i <= m; ++i) { int u, v; cin >> u >> v; e[i] = pii(u, v); } for (int i = 1; i <= q; ++i) { int a, b; cin >> a >> b; que[i] = pii(a, b); if (a == 2) del[b] = true; } for (int i = 1; i <= n; ++i) par[i] = i; for (int i = 1; i <= m; ++i) { if (!del[i]) dsu_union(e[i].first, e[i].second); } for (int i = q; i >= 1; --i) { int type = que[i].first; if (type == 2) { int id = que[i].second; dsu_union(e[id].first, e[id].second); } else { que[i].second = get_father(que[i].second); } } for (int i = 1; i <= n; ++i) { if (get_father(i) == i) dfs(i); } for (int i = 1; i <= n; ++i) { updatePos(tin[i], pii(arr[i], tin[i])); } for (int i = 1; i <= q; ++i) { int type = que[i].first; if (type == 2) continue; int v = que[i].second; pii mx = segMax(tin[v], tout[v]); if (mx.first == 0) cout << 0 << '\n'; else { cout << mx.first << '\n'; updatePos(mx.second, pii(0, 0)); } } }
#include <bits/stdc++.h> long long int mod = 2000000000 + 7; long long int inf = (long long int)(1e18); using namespace std; mt19937 unlucko(chrono::steady_clock::now().time_since_epoch().count()); set<int, greater<int> > s[int(2e5)]; vector<int> a(int(2e5)), sz(int(2e5)), p(int(2e5)); vector<bool> used(int(3e5), false); vector<pair<int, int> > e, q; void fills() { for (int i = 0; i < int(2e5); i++) sz[i] = 1, p[i] = i; } int Link(int a) { if (a == p[a]) return a; return p[a] = Link(p[a]); } void Unite(int a, int b) { a = Link(a); b = Link(b); if (a == b) return; if (sz[a] < sz[b]) swap(a, b); sz[a] += sz[b]; p[b] = a; } int rLink(int a, vector<pair<int, int> > &rp) { if (a == p[a]) return a; int ret = rLink(p[a], rp); rp.push_back({a, p[a]}); return p[a] = ret; } void rUnite(int a, int b, vector<pair<int, int> > &rval, vector<pair<int, int> > &rsz, vector<pair<int, int> > &rp) { a = rLink(a, rp); b = rLink(b, rp); if (a == b) return; if (sz[a] < sz[b]) swap(a, b); rsz.push_back({a, sz[a]}); sz[a] += sz[b]; while (!s[b].empty()) { int x = *s[b].begin(); s[b].erase(s[b].begin()); rval.push_back({b, x}); s[a].insert(x); } rp.push_back({b, b}); p[b] = a; } void rec(int cur) { vector<pair<int, int> > rsz, rp, rval; if (q[cur].first) rUnite(e[q[cur].second].first, e[q[cur].second].second, rval, rsz, rp); if (cur) rec(cur - 1); if (!q[cur].first) { int x = 0, pr = rLink(q[cur].second, rp); if (!s[pr].empty()) x = *s[pr].begin(); cout << x << "\n"; if (s[pr].find(x) != s[pr].end()) s[pr].erase(s[pr].find(x)); } while (!rval.empty()) { int v = rval.back().first, vl = rval.back().second; rval.pop_back(); int pr = rLink(v, rp); if (s[pr].find(vl) != s[pr].end()) s[v].insert(vl), s[pr].erase(s[pr].find(vl)); } while (!rp.empty()) { int v = rp.back().first, pr = rp.back().second; rp.pop_back(); p[v] = pr; } while (!rsz.empty()) { int v = rsz.back().first, zs = rsz.back().second; rsz.pop_back(); sz[v] = zs; } } int main() { iostream::sync_with_stdio(false); cin.tie(0); fills(); int n, m, t; cin >> n >> m >> t; for (int i = 0; i < n; i++) cin >> a[i]; for (int i = 0; i < m; i++) { int x, y; cin >> x >> y; --x; y--; e.push_back({x, y}); } for (int i = 0; i < t; i++) { int x, y; cin >> x >> y; --x; y--; q.push_back({x, y}); if (x) used[y] = true; } for (int i = 0; i < m; i++) { if (used[i]) continue; Unite(e[i].first, e[i].second); } for (int i = 0; i < n; i++) { s[Link(i)].insert(a[i]); } rec(t - 1); }
#include <bits/stdc++.h> using namespace std; template <class C> constexpr int sz(const C &c) { return int(c.size()); } using ll = long long; constexpr const char nl = '\n', sp = ' '; struct StaticGraph { vector<int> ST, TO, A, B; StaticGraph(int V) : ST(V + 1, 0) {} void reserveDiEdges(int maxEdges) { TO.reserve(maxEdges); A.reserve(maxEdges); B.reserve(maxEdges); } void addDiEdge(int from, int to) { ST[from]++; A.push_back(from); B.push_back(to); } void addBiEdge(int v, int w) { addDiEdge(v, w); addDiEdge(w, v); } void build() { partial_sum(ST.begin(), ST.end(), ST.begin()); TO = B; for (int e = 0; e < int(A.size()); e++) TO[--ST[A[e]]] = B[e]; } struct Iterator { const StaticGraph &G; int i; Iterator(const StaticGraph &G, int i) : G(G), i(i) {} Iterator &operator++() { i++; return *this; } int operator*() const { return G.TO[i]; } bool operator!=(const Iterator &it) const { return i != it.i; } }; struct Adj { const StaticGraph &G; int v; Adj(const StaticGraph &G, int v) : G(G), v(v) {} const Iterator begin() const { return Iterator(G, G.ST[v]); } const Iterator end() const { return Iterator(G, G.ST[v + 1]); } }; const Adj operator[](int v) const { return Adj(*this, v); } int size() const { return int(ST.size()) - 1; } }; template <class R, const bool VALUES_ON_EDGES> struct SubtreeQueries { using Data = typename R::Data; using Lazy = typename R::Lazy; int V, ind; vector<int> pre, post, vert; R ops; void updateVertex(int v, const Lazy &val) { ops.update(pre[v], pre[v], val); } void updateSubtree(int v, const Lazy &val) { int l = pre[v] + VALUES_ON_EDGES, r = post[v]; if (l <= r) ops.update(l, r, val); } Data queryVertex(int v) { return ops.query(pre[v], pre[v]); } Data querySubtree(int v) { int l = pre[v] + VALUES_ON_EDGES, r = post[v]; return l <= r ? ops.query(l, r) : R::qdef(); } template <class Forest> void dfs(const Forest &G, int v, int prev) { vert[pre[v] = ++ind] = v; for (int w : G[v]) if (w != prev) dfs(G, w, v); post[v] = ind; } template <class Forest> vector<Data> reorder(const Forest &G, const vector<Data> &A, const vector<int> &roots) { if (roots.empty()) { for (int v = 0; v < V; v++) if (pre[v] == -1) dfs(G, v, -1); } else for (int v : roots) if (pre[v] == -1) dfs(G, v, -1); vector<Data> ret; ret.reserve(V); for (int i = 0; i < V; i++) ret.push_back(A[vert[i]]); return ret; } template <class Forest> SubtreeQueries(const Forest &G, const vector<Data> &A, const vector<int> &roots = vector<int>()) : V(G.size()), ind(-1), pre(V, -1), post(V), vert(V), ops(reorder(G, A, roots)) {} template <class Forest> SubtreeQueries(const Forest &G, const vector<Data> &A, int rt) : SubtreeQueries(G, A, vector<int>{rt}) {} }; template <class C> struct SegmentTreeBottomUp { using Data = typename C::Data; using Lazy = typename C::Lazy; int N; vector<Data> TR; template <class F> SegmentTreeBottomUp(int N, F f) : N(N), TR(N * 2, C::qdef()) { generate(TR.begin() + N, TR.end(), f); for (int i = N - 1; i > 0; i--) TR[i] = C::merge(TR[i * 2], TR[i * 2 + 1]); } template <class It> SegmentTreeBottomUp(It st, It en) : SegmentTreeBottomUp(en - st, [&] { return *st++; }) {} SegmentTreeBottomUp(int N, const Data &vdef) : SegmentTreeBottomUp(N, [&] { return vdef; }) {} void update(int i, const Lazy &v) { for (i += N, TR[i] = C::applyLazy(TR[i], v); i /= 2;) TR[i] = C::merge(TR[i * 2], TR[i * 2 + 1]); } Data query(int l, int r) { Data ql = C::qdef(), qr = C::qdef(); for (l += N, r += N; l <= r; l /= 2, r /= 2) { if (l % 2) ql = C::merge(ql, TR[l++]); if (!(r % 2)) qr = C::merge(TR[r--], qr); } return C::merge(ql, qr); } }; struct C { using Data = pair<int, int>; using Lazy = int; static Data qdef() { return make_pair(0, -1); } static Data merge(const Data &l, const Data &r) { return max(l, r); } static Data applyLazy(const Data &l, const Lazy &r) { return make_pair(r, l.second); } }; struct R { using Data = pair<int, int>; using Lazy = int; static Data qdef() { return C::qdef(); } SegmentTreeBottomUp<C> ST; R(const vector<Data> &A) : ST(A.begin(), A.end()) {} void update(int l, int r, const Lazy &val) { ST.update(l, val); } Data query(int l, int r) { return ST.query(l, r); } }; int main() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); int N, M, Q; cin >> N >> M >> Q; vector<pair<int, int>> A(N + N - 1, C::qdef()); for (int i = 0; i < N; i++) { cin >> A[i].first; A[i].second = i; } vector<pair<int, int>> edges(M); vector<int> UF(N + N - 1, -1); function<int(int)> find = [&](int v) { return UF[v] < 0 ? v : UF[v] = find(UF[v]); }; for (auto &&e : edges) { cin >> e.first >> e.second; --e.first; --e.second; } vector<int> removed(M, false); vector<pair<int, int>> queries(Q); for (int i = 0; i < Q; i++) { cin >> queries[i].first >> queries[i].second; --queries[i].second; if (queries[i].first == 2) removed[queries[i].second] = true; } StaticGraph G(N + N - 1); int cur = N; for (int i = 0; i < M; i++) if (!removed[i]) { int v, w; tie(v, w) = edges[i]; if ((v = find(v)) != (w = find(w))) { G.addDiEdge(cur, v); G.addDiEdge(cur, w); UF[v] = UF[w] = cur; cur++; } } for (int i = Q - 1; i >= 0; i--) { if (queries[i].first == 1) { queries[i].second = find(queries[i].second); } else { int v, w; tie(v, w) = edges[queries[i].second]; if ((v = find(v)) != (w = find(w))) { G.addDiEdge(cur, v); G.addDiEdge(cur, w); UF[v] = UF[w] = cur; cur++; } } } G.build(); vector<int> roots; for (int i = 0; i < N + N - 1; i++) if (find(i) == i) roots.push_back(i); SubtreeQueries<R, false> sbtr(G, A, roots); for (int i = 0; i < Q; i++) if (queries[i].first == 1) { pair<int, int> q = sbtr.querySubtree(queries[i].second); cout << q.first << nl; sbtr.updateVertex(q.second, 0); } return 0; }
#include <bits/stdc++.h> using namespace std; int n, m, q; pair<int, int> query[500005]; pair<int, int> edge[300005]; pair<int, pair<int, int> > se[300005]; vector<int> vec[200005]; int par[200005]; int vi[200005]; int le[200005]; int ri[200005]; int p[200005]; int sz[200005]; pair<int, int> dq[500005]; int ble[500005], bri[500005]; int find(int x) { if (par[x] == x) return x; return find(par[x]); } pair<int, int> tree[800005]; int ssz; void update(int idx, int val) { idx += ssz; tree[idx] = {val, idx - ssz}; idx /= 2; while (idx) { tree[idx] = max(tree[idx * 2], tree[idx * 2 + 1]); idx /= 2; } } pair<int, int> qu(int le, int ri) { pair<int, int> ret = {0, 0}; le += ssz; ri += ssz; while (le <= ri) { if ((le & 1)) ret = max(ret, tree[le++]); if (!(ri & 1)) ret = max(ret, tree[ri--]); le /= 2; ri /= 2; } return ret; } int main() { scanf("%d%d%d", &n, &m, &q); ssz = 1; while (ssz < n) ssz *= 2; for (int i = 1; i <= n; i++) { par[i] = i; vec[i].push_back(i); scanf("%d", &p[i]); } for (int i = 1; i <= m; i++) { int a, b; scanf("%d%d", &a, &b); edge[i] = {a, b}; se[i] = {0x3f3f3f3f, {a, b}}; } for (int i = 0; i < q; i++) { int a, b; scanf("%d%d", &a, &b); query[i] = {a, b}; if (a == 2) { se[b].first = i; } } sort(se + 1, se + 1 + m); for (int i = m; i >= 1; i--) { int a, b; tie(a, b) = se[i].second; a = find(a); b = find(b); if (a == b) continue; if (vec[a].size() > vec[b].size()) swap(a, b); par[a] = b; for (auto x : vec[a]) vec[b].push_back(x); } int idx = 0; for (int i = 1; i <= n; i++) { if (find(i) == i) { for (auto x : vec[i]) { vi[x] = idx++; } } } for (int i = 1; i <= n; i++) { par[i] = i; le[i] = vi[i]; ri[i] = vi[i]; sz[i] = 1; update(vi[i], p[i]); } for (int i = m; i >= 1; i--) { int a, b; tie(a, b) = se[i].second; if (se[i].first != 0x3f3f3f3f) { dq[se[i].first] = {-1, -1}; } a = find(a); b = find(b); if (a == b) continue; if (sz[a] > sz[b]) swap(a, b); if (se[i].first != 0x3f3f3f3f) { dq[se[i].first] = {a, b}; ble[se[i].first] = le[b]; bri[se[i].first] = ri[b]; } par[a] = b; sz[b] += sz[a]; le[b] = min(le[b], le[a]); ri[b] = max(ri[b], ri[a]); } for (int i = 0; i < q; i++) { int a, b; tie(a, b) = query[i]; if (a == 1) { b = find(b); pair<int, int> ret; ret = qu(le[b], ri[b]); printf("%d\n", ret.first); update(ret.second, 0); } else { int x, y; tie(x, y) = dq[i]; if (x == -1 && y == -1) { continue; } par[x] = x; sz[y] -= sz[x]; le[y] = ble[i]; ri[y] = bri[i]; } } return 0; }
#include <bits/stdc++.h> using namespace std; using ll = long long; const int mxn = 3e5 + 1, mxnq = 5e5 + 1; int arr[mxn], q1[mxnq], q2[mxnq], edgesu[mxn], edgesv[mxn], L1[mxn], L2[mxn], mark[mxn]; set<pair<int, int>> LOL[mxn]; struct DSU { int connected; vector<int> par, sz; vector<set<pair<int, int>>> s; void init(int n) { par = sz = vector<int>(n + 1, 0); s = vector<set<pair<int, int>>>(n + 1); for (int i = 1; i <= n; ++i) s[i].insert({arr[i], i}); for (int i = 1; i <= n; i++) { par[i] = i, sz[i] = 1; } connected = n; } int getPar(int u) { if (u != par[u]) return getPar(par[u]); return u; } int getSize(int u) { return sz[getPar(u)]; } int getAns(int u) { int par2 = getPar(u); auto it = *s[par2].rbegin(); s[par2].erase(it); arr[it.second] = 0; s[par2].insert({0, it.second}); return it.first; } void unite(int u, int v, int val) { int par1 = getPar(u), par2 = getPar(v); if (par1 == par2) return; connected--; if (sz[par1] > sz[par2]) swap(par1, par2); for (auto &x : s[par1]) { s[par2].insert(x); } sz[par2] += sz[par1]; par[par1] = par[par2]; if (val) { mark[val] = 1; LOL[val] = s[par1]; L1[val] = par1; L2[val] = par2; } } }; signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); int n, m, q; cin >> n >> m >> q; for (int i = 1; i <= n; ++i) cin >> arr[i]; memset(mark, 0, sizeof(mark)); for (int i = 1; i <= m; ++i) { cin >> edgesu[i] >> edgesv[i]; } for (int i = 1; i <= q; ++i) { cin >> q1[i] >> q2[i]; if (q1[i] == 2) mark[q2[i]] = 1; } DSU dsu; dsu.init(n); for (int i = 1; i <= m; ++i) { if (mark[i]) continue; dsu.unite(edgesu[i], edgesv[i], 0); } memset(mark, 0, sizeof(mark)); for (int i = q; i > 0; --i) { if (q1[i] == 2) dsu.unite(edgesu[q2[i]], edgesv[q2[i]], q2[i]); } for (int i = 1; i <= q; ++i) { if (q1[i] == 1) { cout << dsu.getAns(q2[i]) << '\n'; ; } else { if (mark[q2[i]]) { int I = q2[i]; int val = L2[I]; dsu.s[L1[I]].clear(); for (auto &x : LOL[I]) { dsu.s[val].erase({arr[x.second], x.second}); dsu.s[L1[I]].insert({arr[x.second], x.second}); } dsu.par[L1[I]] = L1[I]; } } } return 0; }
#include <bits/stdc++.h> using namespace std; stack<pair<int, int>> ops; vector<int> uf, score; vector<set<pair<int, int>>> comps; int find(int u) { return uf[u] < 0 ? u : find(uf[u]); } void merge(int u, int v) { int pu = find(u), pv = find(v); if (pu == pv) return; if (uf[pu] > uf[pv]) swap(pu, pv); ops.push({pv, uf[pv]}); for (auto &x : comps[pv]) { comps[pu].insert(x); } uf[pu] += uf[pv]; uf[pv] = pu; } void rollback() { pair<int, int> op = ops.top(); ops.pop(); if (op.first == -1) return; int p = uf[op.first]; uf[p] -= op.second; uf[op.first] = op.second; vector<pair<int, int>> items; for (auto &x : comps[op.first]) { pair<int, int> v = {score[x.second], x.second}; items.push_back(v); comps[p].erase(v); } comps[op.first].clear(); for (auto &x : items) { comps[op.first].insert(x); } } int main() { ios::sync_with_stdio(false); cin.tie(NULL); int n, m, q; cin >> n >> m >> q; score.assign(n, 0); for (auto &x : score) { cin >> x; } vector<pair<int, int>> edges(m); for (auto &x : edges) { cin >> x.first >> x.second; --x.first, --x.second; } vector<bool> erased(m); vector<pair<int, int>> queries(q); for (auto &x : queries) { cin >> x.first >> x.second; --x.second; if (x.first == 2) { erased[x.second] = true; } } cerr << "READING WAS GOOD" << endl; uf.assign(n, -1); comps.assign(n, set<pair<int, int>>()); for (int i = 0; i < n; ++i) { comps[i].insert({score[i], i}); } for (int i = 0; i < m; ++i) { pair<int, int> e = edges[i]; if (!erased[i] && find(e.first) != find(e.second)) { merge(e.first, e.second); } } for (int i = q - 1; i >= 0; --i) { pair<int, int> x = queries[i]; if (x.first == 2) { pair<int, int> e = edges[x.second]; if (find(e.first) != find(e.second)) { merge(e.first, e.second); } else { ops.push({-1, -1}); } } } cerr << "MERGING EVERYTHING WAS GOOD TOO" << endl; for (auto &x : queries) { if (x.first == 1) { int p = find(x.second); pair<int, int> v = *comps[p].rbegin(); cout << v.first << "\n"; score[v.second] = 0; comps[p].erase(v); comps[p].insert({0, v.second}); } else { rollback(); } } }
#include <bits/stdc++.h> using namespace std; const int maxn = 1000005; vector<int> edges[maxn]; int a[maxn], par[maxn], del[maxn]; int n, m, q; pair<int, int> E[maxn], Q[maxn]; int get(int x) { if (par[x] == x) return x; else { return par[x] = get(par[x]); } } void unite(int x, int y) { x = get(x); y = get(y); if (x == y) return; ++n; par[n] = n; par[x] = n; par[y] = n; edges[n].push_back(x); edges[n].push_back(y); } int st[maxn], ed[maxn], timer = 0, vis[maxn], vert[maxn]; void dfs(int x) { vis[x] = 1; st[x] = ++timer; vert[timer] = x; for (auto i : edges[x]) { if (!vis[i]) { dfs(i); } } ed[x] = timer; } pair<int, int> t[maxn << 2]; void build(int node, int b, int e) { if (b == e) { t[node] = {a[vert[b]], b}; return; } int mid = (b + e) >> 1; build(2 * node, b, mid); build(2 * node + 1, mid + 1, e); t[node] = max(t[2 * node], t[2 * node + 1]); } void upd(int node, int b, int e, int idx, int val) { if (idx > e or idx < b) return; if (b == idx && e == idx) { t[node] = {val, -1}; return; } int mid = (b + e) >> 1; upd(2 * node, b, mid, idx, val); upd(2 * node + 1, mid + 1, e, idx, val); t[node] = max(t[2 * node], t[2 * node + 1]); } pair<int, int> query(int node, int b, int e, int i, int j) { if (i > e || j < b) return make_pair(0, -1); if (b >= i && j >= e) return t[node]; int mid = (b + e) >> 1; return max(query(2 * node, b, mid, i, j), query(2 * node + 1, mid + 1, e, i, j)); } int main(int argc, char const *argv[]) { scanf("%d %d %d", &n, &m, &q); for (int i = 1; i <= n; ++i) { scanf("%d", &a[i]); } for (int i = 1; i <= m; ++i) { scanf("%d %d", &E[i].first, &E[i].second); } for (int i = 1; i <= n; ++i) { par[i] = i; } for (int i = 1; i <= q; ++i) { scanf("%d %d", &Q[i].first, &Q[i].second); if (Q[i].first == 2) { del[Q[i].second] = 1; } } for (int i = 1; i <= m; ++i) { if (!del[i]) { unite(E[i].first, E[i].second); } } for (int i = q; i >= 1; --i) { if (Q[i].first == 1) { Q[i].second = get(Q[i].second); } else { unite(E[Q[i].second].first, E[Q[i].second].second); } } for (int i = 1; i <= n; ++i) { if (!vis[i]) { dfs(get(i)); } } build(1, 1, n); for (int i = 1; i <= q; ++i) { if (Q[i].first == 1) { pair<int, int> ans = query(1, 1, n, st[Q[i].second], ed[Q[i].second]); if (ans.first == 0) { printf("0\n"); } else { printf("%d\n", ans.first); upd(1, 1, n, ans.second, 0); } } } return 0; }
#include <bits/stdc++.h> using namespace std; vector<int> snm, nodes_rank; vector<pair<int, int>> tree; pair<int, int> get_max(int v, int vl, int vr, int l, int r) { if (l <= vl && r >= vr) return tree[v]; if (l >= vr || r <= vl) return make_pair(-1, -1); auto mid = (vl + vr) / 2; auto x1 = get_max(2 * v + 1, vl, mid, l, r); auto x2 = get_max(2 * v + 2, mid, vr, l, r); if (x1.first > x2.first) return x1; return x2; } void update(int v, int vl, int vr, int pos, int val) { if (vl + 1 == vr) { tree[v].first = val; tree[v].second = pos; return; } auto mid = (vl + vr) / 2; if (pos < mid) { update(2 * v + 1, vl, mid, pos, val); } else { update(2 * v + 2, mid, vr, pos, val); } auto x1 = tree[2 * v + 1], x2 = tree[2 * v + 2]; if (x1.first > x2.first) tree[v] = x1; else tree[v] = x2; } int get_parent(int v) { if (snm[v] == -1) return v; snm[v] = get_parent(snm[v]); return snm[v]; } int uni(int p1, int p2) { if (nodes_rank[p1] < nodes_rank[p2]) swap(p1, p2); snm[p2] = p1; if (nodes_rank[p1] == nodes_rank[p2]) nodes_rank[p1]++; return p1; } int n; vector<int> euler_tour; vector<pair<int, int>> first_last; vector<bool> dfs_used; vector<vector<int>> graph; void dfs(int v) { if (dfs_used[v]) return; dfs_used[v] = true; euler_tour.push_back(v); first_last[v].first = euler_tour.size() - 1; first_last[v].second = euler_tour.size() - 1; for (auto&& to : graph[v]) { dfs(to); } if (v >= n) { euler_tour.push_back(v); first_last[v].second = euler_tour.size() - 1; } } int main() { ios::sync_with_stdio(false); cin.tie(0); int m, q; cin >> n >> m >> q; vector<long long> p(n), parent; graph.resize(n); nodes_rank.resize(n, 0); snm.resize(n, -1); for (int i = 0; i < n; i++) cin >> p[i]; vector<bool> used(m, false); vector<pair<long long, long long>> edges(m); for (int i = 0; i < m; i++) { cin >> edges[i].first >> edges[i].second; edges[i].first--; edges[i].second--; } vector<pair<int, int>> queries(q); for (int i = 0; i < q; i++) { cin >> queries[i].first >> queries[i].second; queries[i].second--; if (queries[i].first == 2) used[queries[i].second] = true; } for (int i = 0; i < m; i++) if (!used[i]) queries.push_back(make_pair(2, i)); parent.resize(queries.size(), -1); for (int i = queries.size() - 1; i >= 0; i--) { if (queries[i].first == 2) { auto [from, to] = edges[queries[i].second]; auto pfrom = get_parent(from); auto pto = get_parent(to); if (pfrom != pto) { snm.emplace_back(-1); nodes_rank.emplace_back(0); graph.emplace_back(); auto vertex = snm.size() - 1; snm[uni(pfrom, pto)] = vertex; graph[pto].push_back(vertex); graph[vertex].push_back(pto); graph[pfrom].push_back(vertex); graph[vertex].push_back(pfrom); } } else { parent[i] = get_parent(queries[i].second); } } dfs_used.resize(snm.size(), false); first_last.resize(snm.size()); for (int i = 0; i < snm.size(); i++) { if (!dfs_used[i] && snm[i] == -1) dfs(i); } tree.resize(4 * euler_tour.size(), make_pair(-1, -1)); vector<int> cost(euler_tour.size()); for (int i = 0; i < euler_tour.size(); i++) { if (euler_tour[i] < n) { cost[i] = p[euler_tour[i]]; } else { cost[i] = 0; } update(0, 0, euler_tour.size(), i, cost[i]); } for (int i = 0; i < queries.size(); i++) { if (queries[i].first == 1) { auto [second, e] = first_last[parent[i]]; auto x = get_max(0, 0, euler_tour.size(), second, e + 1); cout << x.first << endl; update(0, 0, euler_tour.size(), x.second, 0); } } return 0; }
#include <bits/stdc++.h> using namespace std; vector<pair<int, int> > v, queries; vector<int> adj[1000009]; int val[200009]; int neww, tree[4000009], qvalue[1000009], visited[1000009], endd[1000009], k, p[2000009], n, m, q, present[300009], parent[1000009]; void update(int node, int start, int endd, int ind, int val) { if (start == endd) { tree[node] = val; return; } int mid = (start + endd) / 2; if (ind <= mid) update(2 * node, start, mid, ind, val); else { update(2 * node + 1, mid + 1, endd, ind, val); } tree[node] = max(tree[2 * node], tree[2 * node + 1]); } int query(int node, int start, int endd, int l, int r) { if (start > endd || l > r || start > r || endd < l) return 0; if (start >= l && endd <= r) return tree[node]; int mid = (start + endd) / 2; return max(query(2 * node, start, mid, l, r), query(2 * node + 1, mid + 1, endd, l, r)); } void dfs(int i) { if (visited[i]) return; visited[i] = endd[i] = ++neww; update(1, 1, k, visited[i], p[i]); for (int j = 0; j < adj[i].size(); j++) { dfs(adj[i][j]); endd[i] = max(endd[i], endd[adj[i][j]]); } } int root(int i) { while (parent[i] != i) { parent[i] = parent[parent[i]]; i = parent[i]; } return i; } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cin >> n >> m >> q; for (int i = 1; i <= n; i++) { cin >> p[i]; val[p[i]] = i; parent[i] = i; } for (int i = n + 1; i <= 1000000; i++) parent[i] = i; for (int i = 1; i <= m; i++) { int x, y; cin >> x >> y; v.push_back({x, y}); } k = n + 1; for (int i = 1; i <= q; i++) { int x, y; cin >> x >> y; queries.push_back({x, y}); if (x == 2) present[y] = 1; } for (int i = 1; i <= m; i++) { if (present[i] == 0) { int p1 = root(v[i - 1].first), p2 = root(v[i - 1].second); if (p1 != p2) { adj[k].push_back(p1); adj[k].push_back(p2); parent[p1] = parent[p2] = k; k++; } } } for (int i = q - 1; i >= 0; i--) { if (queries[i].first == 2) { int p1 = root(v[queries[i].second - 1].first), p2 = root(v[queries[i].second - 1].second); if (p1 != p2) { adj[k].push_back(p1); adj[k].push_back(p2); parent[p1] = parent[p2] = k; qvalue[i] = k; k++; } } else { int tt = queries[i].second; int pita = root(tt); qvalue[i] = pita; } } for (int i = k - 1; i >= 1; i--) { if (!visited[i]) dfs(i); } for (int i = 0; i < q; i++) { if (queries[i].first == 1) { int l = visited[qvalue[i]]; int r = endd[qvalue[i]]; int ans = query(1, 1, k, l, r); if (ans) { update(1, 1, k, visited[val[ans]], 0); } cout << ans << "\n"; } } return 0; }
#include <bits/stdc++.h> using namespace std; template <typename T> void __read(T& a) { cin >> a; } template <typename T, typename... Args> void __read(T& a, Args&... args) { cin >> a; __read(args...); } constexpr long long M7 = 1000000007ll; constexpr long long M9 = 1000000009ll; constexpr long long MFFT = 998244353ll; template <class T> void outv(T& a) { for (auto& x : a) cout << x << ' '; } static mt19937 rnd(static_cast<unsigned>( chrono::steady_clock::now().time_since_epoch().count())); auto __fast_io__ = (ios_base::sync_with_stdio(false), cin.tie(nullptr)); int32_t main() { long long n, m, q; __read(n, m, q); vector<long long> p(n); for (signed i = 0; i < (n); i++) cin >> p[i]; vector<pair<long long, long long>> e(m); vector<set<long long>> g(n); for (auto& [v, u] : e) { cin >> v >> u; v--, u--; g[v].insert(u); g[u].insert(v); } vector<pair<long long, long long>> qr(q); for (auto& [t, i] : qr) { cin >> t >> i; i--; t--; if (t) { auto& [v, u] = e[i]; g[v].erase(u); g[u].erase(v); } } vector<vector<long long>> comp; vector<long long> color(n, -1); function<void(long long)> dfs = [&](long long v) { color[v] = comp.size() - 1; comp.back().push_back(v); for (auto& u : g[v]) { if (color[u] == -1) { dfs(u); } } }; for (long long i = 0; i < n; ++i) { if (color[i] == -1) { comp.emplace_back(); dfs(i); } } vector<vector<long long>> z(q); for (long long i = q - 1; i >= 0; --i) { if (qr[i].first) { auto [v, u] = e[qr[i].second]; if (color[v] != color[u]) { if (comp[color[v]].size() > comp[color[u]].size()) { swap(v, u); } z[i] = comp[color[v]]; long long cc = color[v]; for (long long w : comp[cc]) { color[w] = color[u]; comp[color[u]].push_back(w); } comp[cc].clear(); } g[v].insert(u); g[u].insert(v); } } vector<priority_queue<pair<long long, long long>>> d; color.assign(n, -1); function<void(long long)> dfs2 = [&](long long v) { color[v] = d.size() - 1; d.back().emplace(p[v], v); for (long long u : g[v]) { if (color[u] == -1) { dfs2(u); } } }; for (long long v = 0; v < n; ++v) { if (color[v] == -1) { d.emplace_back(); dfs2(v); } } for (long long j = 0; j < q; ++j) { auto& [t, i] = qr[j]; if (t == 0) { long long ind = color[i]; while (color[d[ind].top().second] != ind) { d[ind].pop(); } auto [w, v] = d[ind].top(); cout << w << '\n'; p[v] = 0; d[ind].pop(); d[ind].emplace(0, v); } else { if (!z[j].empty()) { d.emplace_back(); for (auto v : z[j]) { color[v] = d.size() - 1; d.back().emplace(p[v], v); } } } } return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXN = (int)5e5 + 5; const int MAXM = (int)3e5 + 5; const int MAXQ = (int)5e5 + 5; pair<int, int> e[MAXM], que[MAXQ], t[MAXN << 2]; vector<int> adj[MAXN]; int tin[MAXN], tout[MAXN], timer; int par[MAXN], arr[MAXN]; bool del[MAXM]; int n, m, q; int getPar(int x) { if (x == par[x]) { return x; } return par[x] = getPar(par[x]); } void uni(int a, int b) { a = getPar(a); b = getPar(b); if (a == b) { return; } ++n; par[n] = n; par[a] = n; par[b] = n; adj[n].push_back(a); adj[n].push_back(b); } void dfs(int v) { tin[v] = ++timer; for (int to : adj[v]) { dfs(to); } tout[v] = timer; } pair<int, int> segMax(int v, int tl, int tr, int l, int r) { if (l > r || tl > r || tr < l) { return make_pair(0, 0); } if (l <= tl && tr <= r) { return t[v]; } int mid = (tl + tr) >> 1; int c1 = (v << 1), c2 = (c1 | 1); return max(segMax(c1, tl, mid, l, r), segMax(c2, mid + 1, tr, l, r)); } void updPos(int v, int tl, int tr, int p, pair<int, int> x) { if (tl == tr) { t[v] = x; return; } int mid = (tl + tr) >> 1; int c1 = (v << 1), c2 = (c1 | 1); if (p <= mid) { updPos(c1, tl, mid, p, x); } else { updPos(c2, mid + 1, tr, p, x); } t[v] = max(t[c1], t[c2]); } void solve() { scanf("%d %d %d", &n, &m, &q); for (int i = 1; i <= n; ++i) { scanf("%d", &arr[i]); } for (int i = 1; i <= m; ++i) { int u, v; scanf("%d %d", &u, &v); e[i] = make_pair(u, v); } for (int i = 1; i <= q; ++i) { int a, b; scanf("%d %d", &a, &b); que[i] = make_pair(a, b); if (a == 2) { del[b] = 1; } } for (int i = 1; i <= n; ++i) { par[i] = i; } for (int i = 1; i <= m; ++i) { if (!del[i]) { uni(e[i].first, e[i].second); } } for (int i = q; i > 0; --i) { int tp = que[i].first; if (tp == 2) { int id = que[i].second; uni(e[id].first, e[id].second); } else { que[i].second = getPar(que[i].second); } } for (int i = 1; i <= n; ++i) { if (getPar(i) == i) { dfs(i); } } for (int i = 1; i <= n; ++i) { updPos(1, 1, n, tin[i], make_pair(arr[i], tin[i])); } for (int i = 1; i <= q; ++i) { int tp = que[i].first; if (tp == 1) { int v = que[i].second; pair<int, int> tmp = segMax(1, 1, n, tin[v], tout[v]); if (tmp.first == 0) { printf("0\n"); } else { printf("%d\n", tmp.first); updPos(1, 1, n, tmp.second, make_pair(0, 0)); } } } } int main() { int tt = 1; while (tt--) { solve(); } return 0; }
#include <bits/stdc++.h> #pragma GCC optimize("Ofast,unroll-loops,-ffloat-store") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma") using namespace std; const int maxn = 1e5 + 5; int n, m, q, U[maxn * 3], V[maxn * 3], p[maxn << 1]; int tr[maxn * 5], X[maxn * 5]; int sz[maxn << 1], par[maxn << 1], id[maxn << 1]; bool vis[maxn * 5], oke[maxn * 3]; set<int, greater<int> > mys[maxn << 1]; stack<pair<int, int> > st; vector<int> del; void readf() { cin >> n >> m >> q; for (int i = 1; i <= n; ++i) { cin >> p[i]; id[p[i]] = i; } for (int i = 1; i <= m; ++i) cin >> U[i] >> V[i]; for (int i = 1; i <= q; ++i) { cin >> tr[i] >> X[i]; if (tr[i] == 2) { oke[X[i]] = 1; del.emplace_back(X[i]); } } } inline int root(int u) { while (u != par[u]) u = par[u]; return u; } void join(int i, int u, int v) { u = root(u); v = root(v); if (u == v) return; vis[i] = 1; if (sz[u] < sz[v]) swap(u, v); for (auto it : mys[v]) mys[u].insert(it); if (oke[i] == 1) { st.push(pair<int, int>(u, sz[u])); st.push(pair<int, int>(v, par[v])); } sz[u] += sz[v]; par[v] = u; } void roll(int i) { if (vis[i] == 0) return; pair<int, int> it = st.top(); st.pop(); int v = it.first; par[v] = it.second; it = st.top(); st.pop(); int u = it.first; sz[u] = it.second; for (auto it : mys[v]) mys[u].erase(it); } void solve() { for (int i = 1; i <= n; ++i) par[i] = i, sz[i] = 1, mys[i].insert(p[i]); for (int i = 1; i <= m; ++i) if (oke[i] == 0) { join(i, U[i], V[i]); } reverse(del.begin(), del.end()); for (int i : del) { join(i, U[i], V[i]); } for (int i = 1; i <= q; ++i) if (tr[i] == 1) { int u = root(X[i]); if (mys[u].size() == 0) { cout << "0\n"; continue; } else { int tmp = (*mys[u].begin()); cout << tmp << '\n'; u = id[tmp]; mys[u].erase(tmp); while (u != par[u]) { u = par[u]; mys[u].erase(tmp); } } } else roll(X[i]); } int main() { srand(time(NULL)); ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); readf(); solve(); }
#include <bits/stdc++.h> using namespace std; const int oo = (int)1e9; struct NodeP { int val; NodeP *left, *right; NodeP() {} NodeP(int v) { val = v; } }; struct Range { int L, R; Range() {} Range(int a, int b) { L = a; R = b; } bool operator<(const Range& r) const { return R < r.R; } }; struct Event { bool isValid = false; Range original, split1, split2; Event() {} Event(Range a, Range b, Range c) { isValid = true; original = a; split1 = b, split2 = c; } }; struct ST { struct Node { int L, R; pair<int, int> maxVal; Node() {} Node(int a, int b) { L = a; R = b; maxVal = {0, L}; } }; vector<Node> st; ST(int n) { st.resize(4 * n + 10, Node()); init(1, 0, n - 1); } void init(int p, int a, int b) { st[p] = Node(a, b); if (a == b) return; int mid = (a + b) / 2; init(2 * p, a, mid); init(2 * p + 1, mid + 1, b); } void pointUpdate(int p, int pos, long long int val) { Node& now = st[p]; if (pos < now.L || now.R < pos) return; if (pos <= now.L && now.R <= pos) { st[p].maxVal.first = val; return; } pointUpdate(2 * p, pos, val); pointUpdate(2 * p + 1, pos, val); update(p); } pair<int, int> rangeMax(int p, int a, int b) { Node& now = st[p]; if (b < now.L || now.R < a) return {-oo, -1}; if (a <= now.L && now.R <= b) { return st[p].maxVal; } auto ret1 = rangeMax(2 * p, a, b); auto ret2 = rangeMax(2 * p + 1, a, b); update(p); return max(ret1, ret2); } void update(int p) { Node& now = st[p]; now.maxVal = max(st[2 * p].maxVal, st[2 * p + 1].maxVal); } }; vector<int> lefts, rights, leftHead, rightHead; vector<int> par; int find(int i) { if (par[i] == i) return i; return par[i] = find(par[i]); } bool merge(int u, int v) { u = find(u), v = find(v); if (u == v) return false; par[v] = u; int rHead = rightHead[u], lHead = leftHead[v]; rights[rHead] = lHead; lefts[lHead] = rHead; rightHead[u] = rightHead[v]; return true; } void sol() { int n, m, q; cin >> n >> m >> q; vector<int> vals(n); for (int& x : vals) cin >> x; vector<pair<int, int>> queries(q), edges(m); for (int i = 0; i < m; i++) { int x, y; cin >> x >> y; x--; y--; edges[i] = {x, y}; } vector<bool> edgesRem(m); for (int i = 0; i < q; i++) { int type, node; cin >> type >> node; node--; queries[i] = {type, node}; if (type == 2) edgesRem[node] = true; } for (int i = 0; i < m; i++) if (!edgesRem[i]) { queries.push_back({2, i}); } par = vector<int>(n); lefts = rights = leftHead = rightHead = vector<int>(n); auto clearDSU = [&] { for (int i = 0; i < n; i++) { par[i] = i; leftHead[i] = rightHead[i] = i; lefts[i] = rights[i] = i; } }; clearDSU(); for (int i = (int)queries.size() - 1; i >= 0; i--) { auto now = queries[i]; if (now.first != 2) continue; auto edge = edges[now.second]; merge(edge.first, edge.second); } vector<int> arr(n); int ptr = 0; set<Range> curRanges; for (int i = 0; i < n; i++) if (find(i) == i) { int now = lefts[i]; int oPtr = ptr; while (true) { arr[ptr++] = now; if (rights[now] == now) break; now = rights[now]; } curRanges.insert(Range(oPtr, ptr - 1)); } vector<int> pos(n); for (int i = 0; i < n; i++) pos[arr[i]] = i; auto makeRange = [&](int u) { int L = leftHead[u], R = rightHead[u]; if (pos[L] > pos[R]) swap(L, R); return Range(pos[L], pos[R]); }; clearDSU(); vector<Event> events((int)queries.size()); for (int i = (int)queries.size() - 1; i >= 0; i--) { auto now = queries[i]; if (now.first != 2) continue; auto edge = edges[now.second]; int u = find(edge.first), v = find(edge.second); if (u != v) { par[v] = u; int rHead = rightHead[u], lHead = leftHead[v]; Range old1 = makeRange(u), old2 = makeRange(v); rights[rHead] = lHead; lefts[lHead] = rHead; rightHead[u] = rightHead[v]; Range new1 = makeRange(u); events[i] = Event(new1, old1, old2); } } ST st = ST(n); for (int i = 0; i < n; i++) { st.pointUpdate(1, pos[i], vals[i]); } for (int i = 0; i < q; i++) { auto now = queries[i]; if (now.first == 1) { int spot = pos[now.second]; auto who = curRanges.lower_bound(Range(spot, spot)); auto range = *who; auto ans = st.rangeMax(1, range.L, range.R); cout << ans.first << '\n'; st.pointUpdate(1, ans.second, 0); } else { if (events[i].isValid) { curRanges.erase(events[i].original); curRanges.insert(events[i].split1); curRanges.insert(events[i].split2); } } } } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); sol(); return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 10, MAXM = 3e5 + 10, MAXQ = 5e5 + 10; int n, m, q, c[MAXN], st[MAXN], fn[MAXN], S[MAXQ], E[MAXQ], ind[MAXN], p[MAXN]; pair<int, int> edg[MAXM], Q[MAXQ]; vector<int> comp[MAXN], res; bool en[MAXM]; struct node { int mx, l, r; }; node vs[MAXN * 4]; void upd(int v) { if (vs[2 * v + 1].r == 0 || p[vs[2 * v].mx] > p[vs[2 * v + 1].mx]) vs[v].mx = vs[2 * v].mx; else vs[v].mx = vs[2 * v + 1].mx; } void make(int v, int l, int r) { vs[v].l = l, vs[v].r = r; if (r - l == 1) { vs[v].mx = res[l]; return; } int mid = (l + r) / 2; make(2 * v, l, mid); make(2 * v + 1, mid, r); upd(v); } int getmx(int v, int ql, int qr) { if (vs[v].r <= ql || qr <= vs[v].l) return res[ql]; if (ql <= vs[v].l && vs[v].r <= qr) return vs[v].mx; int a = getmx(2 * v, ql, qr); int b = getmx(2 * v + 1, ql, qr); if (p[a] > p[b]) return a; else return b; } void chg(int v, int qi) { if (qi < vs[v].l || vs[v].r <= qi) return; if (qi == vs[v].l && vs[v].r - vs[v].l == 1) return; chg(2 * v, qi); chg(2 * v + 1, qi); upd(v); } void merge(int a, int b) { if (comp[a].size() < comp[b].size()) swap(a, b); if (a == b) return; fn[a] = fn[b]; for (int i = 0; i < comp[b].size(); i++) comp[a].push_back(comp[b][i]), c[comp[b][i]] = a; comp[b].clear(); } int main() { ios::sync_with_stdio(false); cin >> n >> m >> q; for (int i = 1; i <= n; i++) cin >> p[i], c[i] = i, comp[i].push_back(i), st[i] = i, fn[i] = i; for (int i = 0; i < m; i++) cin >> edg[i].first >> edg[i].second; for (int i = 0; i < q; i++) { cin >> Q[i].first >> Q[i].second; if (Q[i].first == 2) { Q[i].second--; en[Q[i].second] = true; } } for (int i = 0; i < m; i++) if (!en[i]) merge(c[edg[i].first], c[edg[i].second]); for (int i = q - 1; i >= 0; i--) if (Q[i].first == 2) merge(c[edg[Q[i].second].first], c[edg[Q[i].second].second]); else S[i] = st[c[Q[i].second]], E[i] = fn[c[Q[i].second]]; for (int i = 1; i <= n; i++) for (int j = 0; j < comp[i].size(); j++) res.push_back(comp[i][j]); for (int i = 0; i < n; i++) ind[res[i]] = i; make(1, 0, n); for (int i = 0; i < q; i++) if (Q[i].first == 1) { int t = getmx(1, ind[S[i]], ind[E[i]] + 1); cout << p[t] << '\n'; p[t] = 0; chg(1, ind[t]); } }
#include <bits/stdc++.h> using namespace std; struct dsu { vector<int> id; vector<int> last; dsu(int n) { id = vector<int>(n); iota(id.begin(), id.end(), 0); last = vector<int>(n); iota(last.begin(), last.end(), 0); } int find(int a) { while (id[a] != a) { id[a] = id[id[a]]; a = id[a]; } return a; } bool unite(int a, int b) { a = find(a); b = find(b); if (a == b) return false; last[a] = last[b]; id[b] = a; return true; } }; class segtree { private: struct node { int mx = 0; int mx_ind = -1; void assign(int ind, int v) { mx = v; mx_ind = ind; } void merge(node &a, node &b) { if (a.mx >= b.mx) { mx_ind = a.mx_ind; } else { mx_ind = b.mx_ind; } mx = max(a.mx, b.mx); } }; int b; node *tree; public: const int n; segtree(int _n) : n(_n) { assert(_n > 0); for (b = 1; b < n; b <<= 1) ; tree = new node[b << 1]; } template <typename... M> void update(int ind, const M &...v) { tree[b + ind].assign(ind, v...); for (int i = (b + ind) / 2; i > 0; i >>= 1) { tree[i].merge(tree[i * 2], tree[i * 2 + 1]); } } node get(int l, int r) const { assert(0 <= l && l <= r && r < n); l += b; r += b; if (l == r) { return tree[l]; } node left = tree[l]; node right = tree[r]; while (l + 1 < r) { if (l % 2 == 0) { left.merge(left, tree[l + 1]); } if (r % 2) { right.merge(tree[r - 1], right); } l /= 2; r /= 2; } node answer; answer.merge(left, right); return answer; } }; void foo() { int n, m, q; cin >> n >> m >> q; vector<int> p(n); for (int i = 0; i < n; i++) { cin >> p[i]; } vector<pair<int, int>> edges; set<int> es; for (int i = 0; i < m; i++) { int x, y; cin >> x >> y; x--; y--; edges.push_back({x, y}); es.insert(i); } struct query { int type; int x; }; vector<query> queries; for (int i = 0; i < q; i++) { int type, x; cin >> type >> x; x--; queries.push_back({type, x}); if (type == 2) { auto it = es.find(x); assert(it != es.end()); es.erase(it); } } for (int ed : es) { queries.push_back({2, ed}); } q = queries.size(); reverse(queries.begin(), queries.end()); dsu g(n); vector<pair<int, int>> info; vector<int> par(n, -1); for (int i = 0; i < q; i++) { const query &qr = queries[i]; if (qr.type == 1) { int rt = g.find(qr.x); info.push_back({rt, g.last[rt]}); } else { assert(qr.type == 2); const pair<int, int> &e = edges[qr.x]; int v = e.first, u = e.second; v = g.find(v); u = g.find(u); assert(par[v] == -1); assert(par[u] == -1); if (v == u) continue; par[u] = g.last[v]; g.unite(v, u); } } reverse(info.begin(), info.end()); vector<int> nxt(n, -1); for (int i = 0; i < n; i++) { if (par[i] != -1) { nxt[par[i]] = i; } } vector<int> roots; for (int i = 0; i < n; i++) { if (par[i] == -1) { roots.push_back(i); } } vector<int> order(n); int next = -1; vector<int> pos(n, -1); for (int i = 0; i < n; i++) { if (next == -1) { order[i] = roots.back(); roots.pop_back(); } else { order[i] = next; } next = nxt[order[i]]; pos[order[i]] = i; } segtree st(n); for (int i = 0; i < n; i++) { st.update(i, p[order[i]]); } for (auto &pr : info) { int index = st.get(pos[pr.first], pos[pr.second]).mx_ind; cout << p[order[index]] << endl; st.update(index, 0); p[order[index]] = 0; } } int main() { ios::sync_with_stdio(0); cin.tie(0); foo(); }
#include <bits/stdc++.h> using namespace std; const int MAX = 5e5 + 9; const int MAX2 = 2e5 + 9; int n, p[MAX2], idx[MAX2], node[(int)5e5 + 9]; vector<int> adj[MAX]; pair<int, int> qu[(int)5e5 + 9], edges[(int)3e5 + 9]; bool vis[(int)3e5 + 9]; int par[MAX]; int dfsCnt, euler[MAX], rangeStart[MAX], rangeEnd[MAX]; int tree[(MAX << 2)]; int N; int FindSet(int node) { if (par[node] == node) { return node; } return par[node] = FindSet(par[node]); } void MergeNodes(int u, int v) { int parU = FindSet(u), parV = FindSet(v); if (parU == parV) { return; } ++n; adj[n].push_back(parU); adj[n].push_back(parV); par[parU] = par[parV] = n; } void Initialize() { for (int i = 1; i < MAX; ++i) { par[i] = i; } } void DFS(int cur, int parent = -1) { ++dfsCnt; (cur <= N ? euler[dfsCnt] = p[cur] : euler[dfsCnt] = 0); rangeStart[cur] = dfsCnt; for (int i = 0; i < adj[cur].size(); ++i) { int child = adj[cur][i]; if (child != parent) { DFS(child, cur); } } rangeEnd[cur] = dfsCnt; } void Build(int low, int high, int pos) { if (low == high) { tree[pos] = euler[low]; return; } int mid = ((low + high) >> 1); Build(low, mid, (pos << 1)); Build(mid + 1, high, (pos << 1 | 1)); tree[pos] = max(tree[(pos << 1)], tree[(pos << 1 | 1)]); } int Query(int low, int high, int pos, int L, int R) { if (L > high || R < low) { return 0; } if (L <= low && R >= high) { return tree[pos]; } int mid = ((low + high) >> 1); return max(Query(low, mid, (pos << 1), L, R), Query(mid + 1, high, (pos << 1 | 1), L, R)); } void Update(int low, int high, int pos, int index) { if (low == high) { tree[pos] = 0; return; } int mid = ((low + high) >> 1); if (index <= mid) Update(low, mid, (pos << 1), index); else Update(mid + 1, high, (pos << 1 | 1), index); tree[pos] = max(tree[(pos << 1)], tree[(pos << 1 | 1)]); } int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); int m, q; cin >> n >> m >> q; N = n; for (int i = 1; i <= n; ++i) { cin >> p[i]; idx[p[i]] = i; } for (int i = 1; i <= m; ++i) { cin >> edges[i].first >> edges[i].second; } for (int i = 1; i <= q; ++i) { cin >> qu[i].first >> qu[i].second; if (qu[i].first == 2) { vis[qu[i].second] = 1; } } Initialize(); for (int i = 1; i <= m; ++i) { if (!vis[i]) { MergeNodes(edges[i].first, edges[i].second); } } for (int i = q; i >= 1; --i) { if (qu[i].first == 1) { node[i] = FindSet(qu[i].second); } else { MergeNodes(edges[qu[i].second].first, edges[qu[i].second].second); } } vector<int> roots; for (int i = 1; i <= n; ++i) { roots.push_back(FindSet(i)); } sort(roots.begin(), roots.end()); roots.erase(unique(roots.begin(), roots.end()), roots.end()); for (int i = 0; i < roots.size(); ++i) { DFS(roots[i]); } Build(1, dfsCnt, 1); for (int i = 1; i <= q; ++i) { if (qu[i].first == 1) { int ans = Query(1, dfsCnt, 1, rangeStart[node[i]], rangeEnd[node[i]]); cout << ans << "\n"; if (ans) { Update(1, dfsCnt, 1, rangeStart[idx[ans]]); } } } return 0; }
#include <bits/stdc++.h> template <class T> inline void rd(T &x) { char c = getchar(), f = 0; x = 0; while (!isdigit(c)) f = (c == '-'), c = getchar(); while (isdigit(c)) x = x * 10 + c - '0', c = getchar(); x = f ? -x : x; } const int MAXN = 1e6 + 7; int fa[MAXN], dfn[MAXN], sz[MAXN], f[MAXN][22], ans[MAXN], pos[MAXN]; std::vector<int> son[MAXN]; int p[MAXN], n, m, tim[MAXN], q, seq[MAXN], wei[MAXN], tot; std::pair<int, int> E[MAXN], Q[MAXN]; int cmax(int x, int y) { return p[x] == p[y] ? (x < y ? x : y) : (p[x] > p[y] ? x : y); } struct Node { int l, r; Node *lc, *rc; int max; Node() {} Node(int l, int r, Node *lc, Node *rc) : l(l), r(r), lc(lc), rc(rc) {} static Node *build(int l, int r) { Node *ret; if (l == r) { ret = new Node(l, r, 0, 0); ret->max = pos[l]; } else { ret = new Node(l, r, build(l, (l + (r - l) / 2)), build((l + (r - l) / 2) + 1, r)); ret->up(); } return ret; } void up() { max = cmax(lc->max, rc->max); } void change(int p, int x) { if (l == r) { ::p[pos[l]] = x; max = pos[l]; return; } if (p <= (l + (r - l) / 2)) lc->change(p, x); else rc->change(p, x); up(); } int query(int L, int R) { if (l == L && r == R) return max; if (R <= (l + (r - l) / 2)) return lc->query(L, R); else if (L > (l + (r - l) / 2)) return rc->query(L, R); else return cmax(lc->query(L, (l + (r - l) / 2)), rc->query((l + (r - l) / 2) + 1, R)); } } * root; bool cmp(int a, int b) { return tim[a] > tim[b]; } inline int find(int x) { return fa[x] == x ? x : fa[x] = find(fa[x]); } void dfs(int u) { static int ts = 0; dfn[u] = ++ts; pos[ts] = u; sz[u] = 1; for (auto v : son[u]) dfs(v), sz[u] += sz[v], f[v][0] = u; } int get(int u, int val) { for (int i = (21); i >= (0); --i) { if (f[u][i] && wei[f[u][i]] >= val) u = f[u][i]; } return u; } int main() { memset(ans, -1, sizeof ans); rd(n), rd(m), rd(q); for (int i = (1); i <= (n); ++i) rd(p[i]), wei[i] = q + 1; for (int i = (1); i <= (2 * n + 5); ++i) fa[i] = i; for (int i = (1); i <= (m); ++i) { rd(E[i].first); rd(E[i].second); tim[i] = q + 1; seq[i] = i; } for (int i = (1); i <= (q); ++i) rd(Q[i].first), rd(Q[i].second); for (int i = (1); i <= (q); ++i) { if (Q[i].first == 2) tim[Q[i].second] = i; } std::sort(seq + 1, seq + m + 1, cmp); tot = n; for (int i = (1); i <= (m); ++i) { int u = E[seq[i]].first, v = E[seq[i]].second, tt = tim[seq[i]]; if (find(u) == find(v)) continue; wei[++tot] = tt; u = find(u), v = find(v); son[tot].push_back(u), son[tot].push_back(v); fa[u] = fa[v] = tot; } for (int i = (tot); i >= (1); --i) if (!dfn[i]) dfs(i); root = Node::build(1, tot); for (int j = (1); j <= (21); ++j) for (int i = (1); i <= (tot); ++i) f[i][j] = f[f[i][j - 1]][j - 1]; for (int i = (1); i <= (q); ++i) { if (Q[i].first == 1) { int v = get(Q[i].second, i); int tmp = root->query(dfn[v], dfn[v] + sz[v] - 1); ans[i] = p[tmp]; if (ans[i]) root->change(dfn[tmp], 0); printf("%d\n", ans[i]); } } return 0; }
#include <bits/stdc++.h> using namespace std; int n, m, q, timer, real_n; vector<int> a, g, ts, te; vector<vector<int>> adj; vector<pair<int, int>> segtree; int get(int u) { return u == g[u] ? u : g[u] = get(g[u]); } void uni(int u, int v) { u = get(u); v = get(v); if (u == v) return; adj.push_back({u, v}); g.push_back(n); g[u] = n; g[v] = n; n++; } void dfs(int u) { segtree.emplace_back(u < real_n ? a[u] : 0, timer); ts[u] = timer++; for (int v : adj[u]) { dfs(v); } te[u] = timer; } int main() { ios::sync_with_stdio(false), cin.tie(nullptr); cin >> n >> m >> q; real_n = n; a.resize(n); for (auto& it : a) cin >> it; vector<array<int, 2>> edges(m); for (auto& it : edges) { cin >> it[0] >> it[1]; --it[0], --it[1]; } vector<array<int, 2>> queries(q); vector<int> erased(m); for (auto& it : queries) { cin >> it[0] >> it[1]; --it[1]; if (it[0] == 2) { erased[it[1]] = true; } } g.resize(n); g.reserve(n * 2); adj.resize(n); adj.reserve(n * 2); iota(g.begin(), g.end(), 0); for (int i = 0; i < m; i++) { if (!erased[i]) { uni(edges[i][0], edges[i][1]); } } vector<int> real_queries; for (int i = q - 1; i >= 0; i--) { if (queries[i][0] == 1) { real_queries.push_back(get(queries[i][1])); } else { auto& e = edges[queries[i][1]]; uni(e[0], e[1]); } } ts.resize(n, -1); te.resize(n, -1); segtree.resize(n, {0, -1}); segtree.reserve(n * 2); for (int i = 0; i < real_n; i++) { int leader = get(i); if (ts[leader] == -1) { dfs(leader); } } for (int i = n - 1; i > 0; i--) { segtree[i] = max(segtree[i << 1], segtree[i << 1 | 1]); } reverse(real_queries.begin(), real_queries.end()); for (int qi : real_queries) { int l = ts[qi] + n, r = te[qi] + n; pair<int, int> res = {0, -1}; for (; l < r; l >>= 1, r >>= 1) { if (l & 1) res = max(res, segtree[l++]); if (r & 1) res = max(res, segtree[--r]); } cout << res.first << '\n'; if (res.first != 0) { int i = res.second + n; segtree[i].first = 0; for (; i >>= 1;) { segtree[i] = max(segtree[i << 1], segtree[i << 1 | 1]); } } } return 0; }
#include <bits/stdc++.h> #pragma GCC optimize("Ofast") using namespace std; template <typename T> void _dbg(char const *s, const T &t) { cerr << s << "=" << t << endl; } template <typename T, typename... TA> void _dbg(char const *s, const T &t, const TA &...ta) { while (*s != ',') cerr << *s++; cerr << "=" << t << ","; _dbg(s + 1, ta...); } template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << "(" << p.first << "," << p.second << ")"; } template <typename T> ostream &print_iterable(ostream &os, T beg, T end) { os << '['; for (auto it = beg; it != end; ++it) { if (it != beg) os << ", "; os << *it; } return os << ']'; } template <typename T, size_t N> ostream &operator<<(ostream &os, const array<T, N> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T> ostream &operator<<(ostream &os, const vector<T> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T> ostream &operator<<(ostream &os, const set<T> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T> ostream &operator<<(ostream &os, const multiset<T> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &x) { return print_iterable(os, begin(x), end(x)); } template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &x) { return print_iterable(os, begin(x), end(x)); } using ll = long long; using ld = long double; using pii = pair<int, int>; using pll = pair<ll, ll>; using pdd = pair<ld, ld>; constexpr int maxn = 2e5 + 1; constexpr int maxq = 5e5 + 1; struct DSU { int par[maxn]; int sz[maxn]; DSU() { iota(par, par + maxn, 0); fill(sz, sz + maxn, 1); } int p(int x) { if (par[x] == x) return x; return par[x] = p(par[x]); } bool merge(int a, int b) { a = p(a); b = p(b); if (a == b) return false; if (sz[a] < sz[b]) { swap(a, b); } sz[a] += sz[b]; par[b] = a; return true; } } dsu; vector<pii> edges; vector<bool> edge_will_be_deleted; vector<int> g[maxn]; vector<pii> qs; array<set<int>, maxn> setik; array<pii, maxq> rollbacks; void solve() { int n, m, q; scanf("%d%d%d", &n, &m, &q); vector<int> used(n + 1); vector<int> p(n); for (auto &x : p) { scanf("%d", &x); } edges.resize(m); edge_will_be_deleted.resize(m, false); for (auto &e : edges) { int a, b; scanf("%d%d", &a, &b); --a, --b; e = {a, b}; g[a].push_back(b); g[b].push_back(a); } qs.resize(q); for (auto &e : qs) { int t, v; scanf("%d%d", &t, &v); --v; e = {t, v}; if (t == 2) { edge_will_be_deleted[v] = true; } } for (int i = 0; i < m; ++i) { if (edge_will_be_deleted[i]) continue; int a, b; tie(a, b) = edges[i]; dsu.merge(a, b); } for (int i = 0; i < n; ++i) { int a = dsu.p(i); setik[a].insert(p[i]); } for (int i = q - 1; i >= 0; --i) { int t, eid; tie(t, eid) = qs[i]; if (t == 2) { int a, b; tie(a, b) = edges[eid]; a = dsu.p(a); b = dsu.p(b); if (a == b) { continue; } if (dsu.sz[a] < dsu.sz[b]) { swap(a, b); } setik[a].insert(setik[b].begin(), setik[b].end()); rollbacks[i] = {a, b}; dsu.merge(a, b); } if (t == 1) { int v = eid; v = dsu.p(v); rollbacks[i] = {v, 0}; } } for (int i = 0; i < q; ++i) { int t, v; tie(t, v) = qs[i]; if (t == 2) { int a, b; tie(a, b) = rollbacks[i]; if (a == b) continue; for (const auto &e : setik[b]) { setik[a].erase(e); } continue; } int p = rollbacks[i].first; int res = 0; while (!setik[p].empty()) { int r = *setik[p].rbegin(); if (!used[r]) { res = r; break; } setik[p].erase(r); } used[res] = true; ; printf("%d\n", res); } } int main() { solve(); return 0; }
#include <bits/stdc++.h> using namespace std; const int MAX = 1e6 + 5; vector<pair<int, int>> edges; vector<pair<int, int>> queries; int nodes[MAX], ds[MAX], currentNode, tourID; bool dels[MAX]; vector<int> ady[MAX]; pair<int, int> stree[4 * MAX]; int idIni[MAX], idFin[MAX]; int dsFind(int v) { if (ds[v] == v) { return v; } return ds[v] = dsFind(ds[v]); } void dsJoin(int u, int v) { u = dsFind(u); v = dsFind(v); if (u == v) return; currentNode++; ds[currentNode] = currentNode; ds[u] = currentNode; ds[v] = currentNode; ady[currentNode].push_back(u); ady[currentNode].push_back(v); } pair<int, int> query(int n, int ini, int fin, int a, int b) { if (ini > b || fin < a) { return make_pair(INT_MIN, INT_MIN); } else if (ini >= a && fin <= b) { return stree[n]; } else { int mid = (ini + fin) / 2; return max(query(n * 2, ini, mid, a, b), query(n * 2 + 1, mid + 1, fin, a, b)); } } void update(int n, int ini, int fin, int p, int v) { if (ini > p || fin < p) { return; } else if (ini >= p && fin <= p) { stree[n] = make_pair(v, p); } else { int mid = (ini + fin) / 2; update(n * 2, ini, mid, p, v); update(n * 2 + 1, mid + 1, fin, p, v); stree[n] = max(stree[n * 2], stree[n * 2 + 1]); } } void dfs(int u) { tourID++; idIni[u] = tourID; for (auto v : ady[u]) { dfs(v); } idFin[u] = tourID; } int main() { cin.tie(0); ios_base::sync_with_stdio(0); memset(stree, -63, sizeof stree); int N, M, Q; cin >> N >> M >> Q; currentNode = N; for (int i = 1; i <= N; i++) { cin >> nodes[i]; } edges.emplace_back(0, 0); queries.emplace_back(0, 0); for (int i = 0; i < M; i++) { int u, v; cin >> u >> v; edges.emplace_back(u, v); } for (int i = 0; i < Q; i++) { int t, v; cin >> t >> v; if (t == 2) { dels[v] = true; } queries.emplace_back(t, v); } for (int i = 1; i <= N; i++) { ds[i] = i; } for (int i = 1; i <= M; i++) { if (!dels[i]) { dsJoin(edges[i].first, edges[i].second); } } for (int i = Q; i > 0; i--) { int t = queries[i].first; int n = queries[i].second; if (t == 1) { queries[i].second = dsFind(n); } else { dsJoin(edges[n].first, edges[n].second); } } for (int i = 1; i < MAX; i++) { if (ds[i] == i) { dfs(i); } } tourID++; for (int i = 1; i <= N; i++) { int p = idIni[i]; update(1, 1, tourID, p, nodes[i]); } for (int i = 1; i <= Q; i++) { int t = queries[i].first; int n = queries[i].second; if (t == 1) { auto res = query(1, 1, tourID, idIni[n], idFin[n]); cout << res.first << "\n"; update(1, 1, tourID, res.second, 0); } } return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 500100; int v[MAXN]; pair<int, int> grafo[MAXN], q[MAXN]; bool are[MAXN]; int p[MAXN]; int pai[MAXN]; vector<int> vec[MAXN]; struct seg { seg *fe, *fd; int meio, l, r; pair<int, int> mex; seg(int x, int y) { meio = (x + y) / 2; l = x, r = y; mex = {-1, 0}; if (l == r) return; fe = new seg(x, meio); fd = new seg(meio + 1, y); } void up(int pos, int novo) { if (l == r) { mex = {novo, l}; return; } if (pos <= meio) fe->up(pos, novo); else fd->up(pos, novo); if (fe->mex.first >= fd->mex.first) mex = fe->mex; else mex = fd->mex; } pair<int, int> get(int a, int b) { if (l >= a && r <= b) return mex; if (l > b || r < a) return {-1, 0}; pair<int, int> re = fe->get(a, b), rd = fd->get(a, b); if (re.first >= rd.first) return re; return rd; } }; int find(int x) { if (pai[x] == x) return x; return pai[x] = find(pai[x]); } void join(int a, int b) { a = find(a), b = find(b); if (vec[a].size() >= vec[b].size()) { for (int i = 0; i < vec[b].size(); i++) vec[a].push_back(vec[b][i]); pai[b] = a; } else { for (int i = 0; i < vec[a].size(); i++) vec[b].push_back(vec[a][i]); pai[a] = b; } } seg st(0, MAXN); int main() { int n, m, Q; scanf("%d %d %d", &n, &m, &Q); for (int i = 1; i <= n; i++) scanf("%d", &v[i]), pai[i] = i, vec[i].push_back(i); for (int i = 1; i <= m; i++) scanf("%d %d", &grafo[i].first, &grafo[i].second); for (int i = 1; i <= Q; i++) { scanf("%d %d", &q[i].first, &q[i].second); if (q[i].first == 2) are[q[i].second] = true; } for (int i = 1; i <= m; i++) { if (are[i] == true) continue; int a = grafo[i].first, b = grafo[i].second; if (find(a) == find(b)) continue; join(a, b); } vector<pair<int, int>> res; for (int i = Q; i >= 1; i--) { if (q[i].first == 1) { int a = find(q[i].second); res.push_back({a, vec[a].size()}); } else { int a = find(grafo[q[i].second].first), b = find(grafo[q[i].second].second); if (a == b) continue; join(a, b); } } for (int i = 1; i < n; i++) { if (find(i) == find(i + 1)) continue; join(i, i + 1); } int h = find(1); for (int i = 0; i < n; i++) p[vec[h][i]] = i + 1, st.up(i + 1, v[vec[h][i]]); for (int i = (int)res.size() - 1; i >= 0; i--) { pair<int, int> h = st.get(p[res[i].first], p[res[i].first] + res[i].second - 1); printf("%d\n", h.first); st.up(h.second, 0); } }
#include <bits/stdc++.h> #pragma GCC optimize(2) using namespace std; inline int read() { int x = 0; int f = 0; char ch = 0; while (!isdigit(ch)) { f |= (ch == '-') ? 1 : 0; ch = getchar(); } while (isdigit(ch)) { x = (x << 3) + (x << 1) + (ch ^ 48); ch = getchar(); } return f ? -x : x; } const int maxn = 6e5 + 10; int aa[maxn]; int st1[maxn], st2[maxn]; int del[maxn], f[maxn]; int typ[maxn], key[maxn]; int n, m, q; int cnt, tim = 0; int in[maxn], out[maxn]; struct node { int to, nxt; } edge[maxn << 1]; int head[maxn], tot = 0; pair<int, int> sum[maxn << 2]; inline void add(int u, int v) { edge[tot].to = v; edge[tot].nxt = head[u]; head[u] = tot++; } inline int fnd(int x) { if (x == f[x]) return x; return f[x] = fnd(f[x]); } inline void link(int u, int v) { u = fnd(u); v = fnd(v); if (u != v) { ++cnt; f[cnt] = cnt; f[u] = f[v] = cnt; add(cnt, u); add(cnt, v); } } inline void dfs(int u) { in[u] = ++tim; for (int i = head[u]; i != -1; i = edge[i].nxt) { int v = edge[i].to; dfs(v); } out[u] = tim; } inline void update(int rt, int x, int l, int r, pair<int, int> k) { if (l > x || r < x) return; if (l == r) { sum[rt] = k; return; } int mid = (l + r) >> 1; update(rt << 1, x, l, mid, k); update(rt << 1 | 1, x, mid + 1, r, k); sum[rt] = max(sum[rt << 1], sum[rt << 1 | 1]); } inline pair<int, int> query(int rt, int l, int r, int al, int ar) { if (l > ar || r < al) return make_pair(0, 0); if (l <= al && r >= ar) return sum[rt]; int mid = (al + ar) >> 1; return max(query(rt << 1, l, r, al, mid), query(rt << 1 | 1, l, r, mid + 1, ar)); } int main() { n = read(); m = read(); q = read(); cnt = n; memset(head, -1, sizeof(head)); for (register int i = 1; i <= n; ++i) aa[i] = read(), f[i] = i; for (register int i = 1; i <= m; ++i) { int u = read(); int v = read(); st1[i] = u; st2[i] = v; } for (register int i = 1; i <= q; ++i) { typ[i] = read(); key[i] = read(); if (typ[i] == 2) { del[key[i]] = 1; } } for (register int i = 1; i <= m; ++i) if (!del[i]) { link(st1[i], st2[i]); } for (register int i = q; i >= 1; --i) { if (typ[i] == 2) { link(st1[key[i]], st2[key[i]]); } else key[i] = fnd(key[i]); } for (register int i = 1; i <= cnt; ++i) if (fnd(i) == i) dfs(i); for (register int i = 1; i <= n; ++i) update(1, in[i], 1, cnt, make_pair(aa[i], in[i])); for (register int i = 1; i <= q; ++i) { if (typ[i] == 1) { pair<int, int> tmp = query(1, in[key[i]], out[key[i]], 1, cnt); printf("%d\n", tmp.first); if (tmp.first) update(1, tmp.second, 1, cnt, make_pair(0, 0)); } } }
#include <bits/stdc++.h> using namespace std; const int mod = 1000000007; const long double pi = std::acos(-1); long long gcd(long long a, long long b) { if (!b) { return a; } return gcd(b, a % b); } long long gcdE(long long a, long long b, long long* x, long long* y) { if (!a) { *x = 0; *y = 1; return b; } long long x1, y1; long long _gcd = gcdE(b % a, a, &x1, &y1); *x = y1 - (b / a) * x1; *y = x1; return _gcd; } long long power(long long x, long long y) { long long res = 1; while (y) { if (y & 1) { res = (res * x) % mod; } y >>= 1; x = (x * x) % mod; } return res; } long long inverse(long long x) { return power(x, mod - 2); } int n, m, q; vector<int> p(1000001, 0); vector<int> b(1000001, 0); vector<pair<int, int>> edges(300001); vector<bool> exists(300001, 1); vector<pair<int, int>> query(500001); vector<int> dsuparent(500001); vector<int> adj[500001]; vector<pair<int, int>> node; vector<pair<int, int>> segtree; int timer = 0; vector<int> in(1000001), out(1000001); vector<int> conv(1000001); void dfs(int c) { in[c] = ++timer; for (int x : adj[c]) { dfs(x); } out[c] = ++timer; } int find(int i) { if (dsuparent[i] != i) { dsuparent[i] = find(dsuparent[i]); } return dsuparent[i]; } void add(int x, int y) { int xroot = find(x); int yroot = find(y); if (xroot == yroot) { return; } adj[++n].push_back(xroot); adj[n].push_back(yroot); dsuparent[xroot] = dsuparent[yroot] = dsuparent[n] = n; } void dsuinit() { for (int i = 1; i <= n; i++) { dsuparent[i] = i; } } pair<int, int> getsum(int ns, int ne, int qs, int qe, int ci) { if (qs <= ns && qe >= ne) { return segtree[ci]; } if (qe < ns || ne < qs) { return {-1, -1}; } int mid = ns + ((ne - ns) >> 1); return max(getsum(ns, mid, qs, qe, (ci << 1) + 1), getsum(mid + 1, ne, qs, qe, (ci << 1) + 2)); } pair<int, int> segquery(int qs, int qe) { return getsum(0, timer - 1, qs, qe, 0); } void updatef(int ns, int ne, int i, int ci) { if (i < ns || i > ne) { return; } if (ns == ne) { segtree[ci] = {0, 0}; return; } int mid = ns + ((ne - ns) >> 1); updatef(ns, mid, i, (ci << 1) + 1); updatef(mid + 1, ne, i, (ci << 1) + 2); segtree[ci] = max(segtree[(ci << 1) + 1], segtree[(ci << 1) + 2]); } void update(int index) { updatef(0, timer - 1, index, 0); } pair<int, int> construct(int si, int ei, int ci) { if (si == ei) { segtree[ci] = {b[si + 1], si + 1}; return segtree[ci]; } int mid = si + ((ei - si) >> 1); segtree[ci] = max(construct(si, mid, (ci << 1) + 1), construct(mid + 1, ei, (ci << 1) + 2)); return segtree[ci]; } void init() { for (int i = 1; i <= n; i++) { b[in[i]] = b[out[i]] = p[i]; conv[in[i]] = conv[out[i]] = i; } segtree.resize((timer << 2) + 1); construct(0, timer - 1, 0); } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n >> m >> q; for (int i = 1; i <= n; i++) { cin >> p[i]; } dsuinit(); for (int i = 1; i <= m; i++) { cin >> edges[i].first >> edges[i].second; } for (int i = 1; i <= q; i++) { cin >> query[i].first >> query[i].second; if (query[i].first == 2) { exists[query[i].second] = 0; } } for (int i = 1; i <= m; i++) { if (exists[i]) { add(edges[i].first, edges[i].second); } } for (int i = q; i >= 1; i--) { if (query[i].first == 2) { add(edges[query[i].second].first, edges[query[i].second].second); continue; } query[i].second = find(query[i].second); } for (int i = 1; i <= n; i++) { if (find(i) == i) { dfs(i); } } init(); for (int i = 1; i <= q; i++) { if (query[i].first == 1) { pair<int, int> get = segquery(in[query[i].second] - 1, out[query[i].second] - 1); cout << get.first << "\n"; get.second = conv[get.second]; if (get.second >= 1) { update(in[get.second] - 1); update(out[get.second] - 1); } } } }
#include <bits/stdc++.h> using namespace std; int const maxn = 400003; int n = 0, m = 0, q = 0, cPoint = 0; int p[maxn]; struct Edge { int u, e; int id; }; Edge E[maxn]; int deleteTime[maxn]; inline bool operator<(Edge const &lhs, Edge const &rhs) { return deleteTime[lhs.id] > deleteTime[rhs.id]; } int opt[500003], Sec[500003]; int head[maxn], nxt[maxn], to[maxn], cnt = 0; inline void insert(int u, int e) { nxt[++cnt] = head[u]; head[u] = cnt; to[cnt] = e; } int fath[maxn]; inline int find(int x) { return fath[x] == x ? x : fath[x] = find(fath[x]); } int ti[maxn]; void CreateTheTree() { std::sort(E + 1, E + m + 1); for (int i = 1; i <= 2 * n; ++i) fath[i] = i; cPoint = n; for (int i = 1; i <= m; ++i) { if (find(E[i].u) == find(E[i].e)) continue; ++cPoint; ti[cPoint] = deleteTime[E[i].id]; insert(cPoint, find(E[i].u)); insert(cPoint, find(E[i].e)); fath[find(E[i].u)] = cPoint; fath[find(E[i].e)] = cPoint; } } int fa[20][maxn], Ldfn[maxn], Rdfn[maxn]; int dfn[maxn], idfn[maxn]; void dfs(int x, int f) { fa[0][x] = f; for (int j = 1; j <= 18; ++j) fa[j][x] = fa[j - 1][fa[j - 1][x]]; if (x <= n) { Ldfn[x] = Rdfn[x] = dfn[x] = ++dfn[0]; idfn[dfn[x]] = x; return; } Ldfn[x] = cPoint + 1, Rdfn[x] = 0; for (int i = head[x]; i; i = nxt[i]) { dfs(to[i], x); Ldfn[x] = std::min(Ldfn[x], Ldfn[to[i]]); Rdfn[x] = std::max(Rdfn[x], Rdfn[to[i]]); } } struct MX { int v, pos; }; MX operator|(MX const &lhs, MX const &rhs) { return lhs.v > rhs.v ? lhs : rhs; } MX mx[maxn << 2]; void CreateSeg(int po, int L, int R) { if (L == R) { mx[po].v = p[idfn[L]]; mx[po].pos = idfn[L]; return; } int mid = (L + R) >> 1; CreateSeg(po << 1, L, mid); CreateSeg(po << 1 | 1, mid + 1, R); mx[po] = mx[po << 1] | mx[po << 1 | 1]; } void Modify(int po, int L, int R, int x) { if (L == R) { mx[po].v = p[idfn[L]]; return; } int mid = (L + R) >> 1; if (x <= mid) Modify(po << 1, L, mid, x); else Modify(po << 1 | 1, mid + 1, R, x); mx[po] = mx[po << 1] | mx[po << 1 | 1]; } MX query(int po, int L, int R, int l, int r) { if (l <= L && R <= r) return mx[po]; int mid = (L + R) >> 1; if (r <= mid) return query(po << 1, L, mid, l, r); else if (l > mid) return query(po << 1 | 1, mid + 1, R, l, r); else return query(po << 1, L, mid, l, r) | query(po << 1 | 1, mid + 1, R, l, r); } int jump(int x, int time) { for (int j = 18; ~j; --j) if (ti[fa[j][x]] > time) x = fa[j][x]; return x; } int main() { scanf("%d %d %d", &n, &m, &q); for (int i = 1; i <= n; ++i) scanf("%d", p + i); for (int i = 1; i <= m; ++i) { scanf("%d %d", &E[i].u, &E[i].e); E[i].id = i; deleteTime[i] = q + 1; } for (int i = 1; i <= q; ++i) { scanf("%d %d", opt + i, Sec + i); if (opt[i] == 2) deleteTime[Sec[i]] = i; } CreateTheTree(); for (int i = 1; i <= cPoint; ++i) if (fath[i] == i) dfs(i, 0); CreateSeg(1, 1, n); for (int i = 1; i <= q; ++i) if (opt[i] == 1) { int x = jump(Sec[i], i); MX res = query(1, 1, n, Ldfn[x], Rdfn[x]); printf("%d\n", res.v); p[res.pos] = 0; Modify(1, 1, n, dfn[res.pos]); } return 0; }
#include <bits/stdc++.h> using namespace std; const long long sz = 2e5 + 10, esz = 3e5 + 10, qsz = 5e5 + 10; int p[sz], erased[esz], par[sz], siz[sz]; struct info { long long a, b; } edge[esz], qry[qsz]; struct rollback { int par, node, siz; } chng[qsz]; long long findp(long long u) { if (par[u] == u) return u; return findp(par[u]); } vector<int> lst[sz]; const bool cmp(int &a, int &b) { return p[a] < p[b]; } void dsu_uni(int u, int v, int id = 0) { int pu = findp(u), pv = findp(v); if (pu == pv) return; if (siz[pu] < siz[pv]) swap(pu, pv); if (id != 0) chng[id] = {pu, pv, siz[pu]}; par[pv] = pu; lst[pu].insert(lst[pu].end(), lst[pv].begin(), lst[pv].end()); siz[pu] += siz[pv]; } int main() { long long n, m, q; cin >> n >> m >> q; for (long long i = 1; i <= n; ++i) scanf("%d", &p[i]); for (long long i = 1; i <= m; ++i) scanf("%lld", &edge[i].a), scanf("%lld", &edge[i].b); for (long long i = 1; i <= q; ++i) { scanf("%lld", &qry[i].a), scanf("%lld", &qry[i].b); if (qry[i].a == 2) erased[qry[i].b] = 1; } for (long long i = 1; i <= n; ++i) par[i] = i, siz[i] = 1, lst[i].push_back(i); for (long long i = 1; i <= m; ++i) { if (erased[i]) continue; dsu_uni(edge[i].a, edge[i].b); } for (long long i = q; i >= 1; --i) { if (qry[i].a == 1) continue; long long id = qry[i].b; dsu_uni(edge[id].a, edge[id].b, i); } for (long long i = 1; i <= n; ++i) sort(lst[i].begin(), lst[i].end(), cmp); for (long long i = 1; i <= q; ++i) { if (qry[i].a == 1) { long long pu = findp(qry[i].b); while (!lst[pu].empty()) { long long now = lst[pu].back(), pnow = findp(now); if (pnow != pu || p[now] == 0) { lst[pu].pop_back(); continue; } break; } long long ans = 0; if (!lst[pu].empty()) ans = p[lst[pu].back()], p[lst[pu].back()] = 0; printf("%lld\n", ans); } else { par[chng[i].node] = chng[i].node; siz[chng[i].par] = chng[i].siz; } } return 0; }
#include <bits/stdc++.h> using namespace std; int n, m, q, r = 1, tmp, op[500005], x[500005], a[500005], w[500005], tim[300005], be[500005], ed[500005], fp[500005]; int tot, head[500005]; int fo[500005], nxt[500005]; int t[500005 * 4]; int finds(int x) { return w[x] == x ? x : w[x] = finds(w[x]); } void link(int u, int to) { u = finds(u), to = finds(to); if (u == to) return; ++n; w[n] = n; w[to] = n; w[u] = n; fo[++tot] = to; nxt[tot] = head[n]; head[n] = tot; fo[++tot] = u; nxt[tot] = head[n]; head[n] = tot; } void dfs(int u) { fp[be[u] = ++tmp] = u; for (int i = head[u]; i; i = nxt[i]) dfs(fo[i]); ed[u] = tmp; } int cma(int x, int y) { return a[x] > a[y] ? x : y; } void build(int l, int r, int i) { t[i] = fp[l]; if (l == r) return; build(l, (l + r) / 2, i * 2 + 1); build((l + r) / 2 + 1, r, i * 2 + 2); t[i] = cma(t[i * 2 + 1], t[i * 2 + 2]); } void upd(int pos, int l, int r, int i) { if (l > r) return; t[i] = fp[l]; if (l == r) return; if (pos <= (l + r) / 2) upd(pos, l, (l + r) / 2, i * 2 + 1); else upd(pos, (l + r) / 2 + 1, r, i * 2 + 2); t[i] = cma(t[i * 2 + 1], t[i * 2 + 2]); } int quy(int L, int R, int l, int r, int i) { if (L > R) return 0; if (L <= l && R >= r) return t[i]; int res = 0; if (L <= (l + r) / 2) res = cma(res, quy(L, R, l, (l + r) / 2, i * 2 + 1)); if (R > (l + r) / 2) res = cma(res, quy(L, R, (l + r) / 2 + 1, r, i * 2 + 2)); return res; } int main() { cin >> n >> m >> q; for (int i = (1); i <= (n); i++) scanf("%d", &a[i]), w[i] = i; w[n + 1] = n + 1; for (int i = (1); i <= (m); i++) scanf("%d%d", &be[i], &ed[i]); for (int i = (1); i <= (q); i++) { scanf("%d%d", &op[i], &x[i]); if (op[i] == 2) tim[x[i]] = 1; } for (int i = (1); i <= (m); i++) if (!tim[i]) link(be[i], ed[i]); for (int i = (q); i >= (1); i--) { if (op[i] == 2) link(be[x[i]], ed[x[i]]); if (op[i] == 1) x[i] = finds(x[i]); } for (int i = (1); i <= (n); i++) if (w[i] == i) dfs(i); build(1, n, 0); for (int i = (1); i <= (q); i++) { if (op[i] == 2) continue; x[i] = quy(be[x[i]], ed[x[i]], 1, n, 0); printf("%d\n", a[x[i]]); a[x[i]] = 0; upd(be[x[i]], 1, n, 0); } }
#include <bits/stdc++.h> using namespace std; using pr = pair<int, int>; int N, M, Q, A[200005], par[200005]; pr E[300005], QS[500005]; bool chk[300005]; set<int> s[200005]; stack<pr> st; int f(int x) { return par[x] = (par[x] == x ? x : f(par[x])); } void uni(int x, int y) { x = f(x), y = f(y); if (x == y) return; if (s[x].size() > s[y].size()) swap(x, y); st.push(pr(x, y)); for (auto it : s[x]) s[y].insert(it); par[x] = y; } int main() { ios::sync_with_stdio(0), cin.tie(0); cin >> N >> M >> Q; iota(par, par + N + 1, 0); for (int i = 1; i <= N; i++) cin >> A[i], s[i].insert(A[i]); for (int i = 1, x, y; i <= M; i++) { cin >> x >> y; E[i] = pr(x, y); } for (int i = 1, x, y; i <= Q; i++) { cin >> x >> y; QS[i] = pr(x, y); if (x == 2) chk[y] = 1; } for (int i = 1; i <= M; i++) if (!chk[i]) uni(E[i].first, E[i].second); for (int i = Q; i; i--) { if (QS[i].first == 1) QS[i].second = f(QS[i].second); else { int x = E[QS[i].second].first, y = E[QS[i].second].second; if (f(x) == f(y)) QS[i].first = 0; else uni(x, y); } } for (int i = 1; i <= Q; i++) { if (QS[i].first == 1) { int p = QS[i].second; int ans = 0; if (s[p].size() > 0) { ans = *s[p].rbegin(); s[p].erase(ans); } cout << ans << "\n"; } else if (QS[i].first == 2) { int x = st.top().first, y = st.top().second; st.pop(); set<int> tmp; for (auto it : s[x]) if (s[y].find(it) != s[y].end()) { tmp.insert(it); s[y].erase(it); } s[x] = tmp; } } }
#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 10; int n, m, q; int p[N]; int wei[N], w[N]; int tim[N], seq[N]; struct edge { int l, r; } e[N]; struct query { int l, r, id; } qq[N]; int tot; int find(int x) { if (x == p[x]) return x; return p[x] = find(p[x]); } int cmp(int a, int b) { return tim[a] > tim[b]; } int ans[N]; vector<int> g[N]; int in[N], out[N], num, pre[N], f[N][21]; int tr[N << 2]; void dfs(int u) { in[u] = ++num; pre[num] = u; for (int j = 1; j <= 20; j++) f[u][j] = f[f[u][j - 1]][j - 1]; for (auto &j : g[u]) { f[j][0] = u; dfs(j); } out[u] = num; } void pushup(int rt) { if (w[tr[rt << 1]] >= w[tr[rt << 1 | 1]]) { tr[rt] = tr[rt << 1]; } else tr[rt] = tr[rt << 1 | 1]; } int get(int x, int t) { for (int i = 20; i >= 0; i--) if (f[x][i] && wei[f[x][i]] >= t) x = f[x][i]; return x; } void build(int rt, int l, int r) { if (l == r) { tr[rt] = pre[l]; return; } int mid = l + r >> 1; build(rt << 1, l, mid); build(rt << 1 | 1, mid + 1, r); pushup(rt); } int query(int rt, int L, int R, int l, int r) { if (L <= l && R >= r) { return tr[rt]; } int mid = l + r >> 1; int res = 0, res1 = 0, res2 = 0; if (L <= mid) res1 = query(rt << 1, L, R, l, mid); if (R > mid) res2 = query(rt << 1 | 1, L, R, mid + 1, r); if (w[res1] >= w[res2]) res = res1; else res = res2; return res; } void update(int rt, int L, int C, int l, int r) { if (l == r) { w[pre[l]] = C; tr[rt] = pre[l]; return; } int mid = l + r >> 1; if (L <= mid) update(rt << 1, L, C, l, mid); else update(rt << 1 | 1, L, C, mid + 1, r); pushup(rt); } int main() { scanf("%d%d%d", &n, &m, &q); for (int i = 1; i <= n; i++) scanf("%d", &w[i]), wei[i] = q + 1; for (int i = 1; i <= n + n + 10; i++) p[i] = i; for (int i = 1; i <= m; i++) { scanf("%d%d", &e[i].l, &e[i].r); tim[i] = q + 1; seq[i] = i; } for (int i = 1; i <= q; i++) { scanf("%d%d", &qq[i].l, &qq[i].r); qq[i].id = i; if (qq[i].l == 2) tim[qq[i].r] = i; } sort(seq + 1, seq + m + 1, cmp); tot = n; for (int i = 1; i <= m; i++) { int u = e[seq[i]].l, v = e[seq[i]].r, t = tim[seq[i]]; int fx = find(u), fy = find(v); if (fx == fy) continue; wei[++tot] = t; g[tot].push_back(fx); g[tot].push_back(fy); p[fx] = tot, p[fy] = tot; } for (int i = tot; i >= 1; i--) if (!in[i]) dfs(i); build(1, 1, num); for (int i = 1; i <= q; i++) { if (qq[i].l == 1) { int v = get(qq[i].r, i); int tmp = query(1, in[v], out[v], 1, num); ans[i] = w[tmp]; if (ans[i]) update(1, in[tmp], 0, 1, num); printf("%d\n", ans[i]); } } }
#include <bits/stdc++.h> using namespace std; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); int rnd(int l, int r) { return l + rng() % (r - l + 1); } using ii = pair<int, int>; using ll = long long; using ull = unsigned long long; const int N = 5e5 + 5; int n, m, q, a[2 * N], id[2 * N], o[N]; ii it[N << 3], ed[N], qu[N]; vector<int> ad[N]; int tin[N], tout[N], idx; int root(int x) { return id[x] == x ? x : id[x] = root(id[x]); } void join(int u, int v) { u = root(u), v = root(v); if (u == v) return; n++; id[n] = n; id[u] = n; id[v] = n; ad[n].push_back(u); ad[n].push_back(v); } void upd(int i, int l, int r, int pos, ii val) { if (pos < l || pos > r) return; if (l == r) { it[i] = val; return; } int mid = l + (r - l) / 2; upd(2 * i, l, mid, pos, val); upd(2 * i + 1, mid + 1, r, pos, val); it[i] = max(it[2 * i], it[2 * i + 1]); } ii que(int i, int l, int r, int u, int v) { if (v < l || u > r) return make_pair(0, 0); if (u <= l && r <= v) return it[i]; int mid = l + (r - l) / 2; return max(que(2 * i, l, mid, u, v), que(2 * i + 1, mid + 1, r, u, v)); } int32_t main() { ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0); if (fopen("graph" ".inp", "r")) { freopen( "graph" ".inp", "r", stdin); freopen( "graph" ".out", "w", stdout); } cin >> n >> m >> q; for (int i = 1, _c = n; i <= _c; ++i) cin >> a[i]; for (int i = 1, _c = n + m; i <= _c; ++i) id[i] = i; for (int i = 1, _c = m; i <= _c; ++i) cin >> ed[i].first >> ed[i].second; for (int i = 1, _c = q; i <= _c; ++i) { cin >> qu[i].first >> qu[i].second; if (qu[i].first == 2) o[qu[i].second] = 1; } for (int i = 1, _c = m; i <= _c; ++i) if (!o[i]) { join(ed[i].first, ed[i].second); } for (int i = q, _c = 1; i >= _c; --i) if (qu[i].first == 2) { int x = qu[i].second; join(ed[x].first, ed[x].second); } else { qu[i].second = root(qu[i].second); } function<void(int)> dfs = [&](int u) { tin[u] = ++idx; for (auto &v : ad[u]) { dfs(v); } tout[u] = idx; }; for (int i = 1, _c = n; i <= _c; ++i) if (root(i) == i) dfs(i); for (int i = 1, _c = n; i <= _c; ++i) upd(1, 1, n, tin[i], make_pair(a[i], tin[i])); for (int i = 1, _c = q; i <= _c; ++i) if (qu[i].first == 1) { int u = qu[i].second; ii ans = que(1, 1, n, tin[u], tout[u]); cout << ans.first << '\n'; upd(1, 1, n, ans.second, make_pair(0, ans.second)); } }
#include <bits/stdc++.h> using namespace std; const long long q = 239017; const long long mod = 1e9 + 7; const long long mod2 = 1e9 + 13; const long long N = 2e5 + 100; const long long M = 3e5 + 100; const long long L = 26; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); long long p[N]; pair<long long, long long> seg[N]; vector<long long> comp[N]; long long c[N]; pair<long long, long long> qrSeg[N + M]; bitset<M> del; long long get(long long a) { if (p[a] == a) return a; return p[a] = get(p[a]); } void merge(long long a, long long b) { a = get(a); b = get(b); if (a == b) return; if ((long long)comp[a].size() < (long long)comp[b].size()) swap(a, b); p[b] = a; seg[a].second = seg[b].second; for (long long el : comp[b]) comp[a].push_back(el); comp[b].clear(); } struct SegTree { vector<long long> t, id; long long n; void update(long long v) { t[v] = max(t[v * 2], t[v * 2 + 1]); if (t[v * 2] > t[v * 2 + 1]) id[v] = id[v * 2]; else id[v] = id[v * 2 + 1]; } void build(long long tl, long long tr, long long v, vector<long long>& a) { if (tl + 1 == tr) { t[v] = a[tl]; id[v] = tl; return; } long long mid = (tl + tr) >> 1; build(tl, mid, v * 2, a); build(mid, tr, v * 2 + 1, a); update(v); } SegTree(vector<long long>& a) { if (a.empty()) return; n = (long long)a.size(); t.resize(4 * n); id.resize(4 * n); build(0, n, 1, a); } void del(long long tl, long long tr, long long v, long long k) { if (tl > k || tr <= k) return; if (tl + 1 == tr && tl == k) { t[v] = 0; return; } long long mid = (tl + tr) >> 1; del(tl, mid, v * 2, k); del(mid, tr, v * 2 + 1, k); update(v); } pair<long long, long long> get_mx(long long tl, long long tr, long long v, long long l, long long r) { if (tr <= l || tl >= r) return {-(long long)1e18, 1337}; if (l <= tl && tr <= r) return {t[v], id[v]}; long long mid = (tl + tr) >> 1; auto a = get_mx(tl, mid, v * 2, l, r); auto b = get_mx(mid, tr, v * 2 + 1, l, r); return (a.first > b.first ? a : b); } pair<long long, long long> get_mx(long long l, long long r) { return get_mx(0, n, 1, l, r + 1); } }; void $main() { long long n, m, q; cin >> n >> m >> q; for (long long i = 0; i < n; ++i) cin >> c[i]; for (long long i = 0; i < n; ++i) { p[i] = i; seg[i] = {i, i}; comp[i].push_back(i); } vector<pair<long long, long long> > r; for (long long i = 0; i < m; ++i) { long long a, b; cin >> a >> b; --a; --b; r.emplace_back(a, b); } vector<pair<long long, long long> > qr; for (long long i = 0; i < q; ++i) { long long a, b; cin >> a >> b; --b; qr.emplace_back(a, b); if (a != 1) del[b] = 1; } for (long long i = 0; i < m; ++i) if (!del[i]) qr.emplace_back(2, i); reverse(qr.begin(), qr.end()); long long it = 0; for (auto el : qr) { if (el.first == 2) { merge(r[el.second].first, r[el.second].second); } else { qrSeg[it++] = seg[get(el.second)]; } } for (long long i = 0; i < n; ++i) merge(0, i); long long root = get(0); for (long long i = 0; i < (long long)comp[root].size(); ++i) p[comp[root][i]] = i; for (long long i = 0; i < it; ++i) qrSeg[i] = {p[qrSeg[i].first], p[qrSeg[i].second]}; for (long long& el : comp[root]) el = c[el]; SegTree tree = SegTree(comp[root]); for (long long i = it - 1; i >= 0; --i) { auto get = tree.get_mx(qrSeg[i].first, qrSeg[i].second); cout << get.first << '\n'; tree.del(0, n, 1, get.second); } } int main() { ios_base::sync_with_stdio(0); cin.tie(0), cout.tie(0); $main(); return 0; }
#include <bits/stdc++.h> using namespace std; const long long mod = 1000000007; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); int rnd(int l, int r) { uniform_int_distribution<int> uni(l, r); return uni(rng); } long long powmod(long long a, long long b) { long long res = 1; a %= mod; assert(b >= 0); for (; b; b >>= 1) { if (b & 1) res = res * a % mod; a = a * a % mod; } return res; } int n, m, q; int dsu[700066], tot; pair<int, int> E[300066], query[500066]; bool vis[300066]; vector<int> e[700066], vec[700066], V; int p[200066]; int ans[500066]; int dfn[700066], tot_dfn, siz[700066]; set<int> Set; pair<int, int> node[200066 * 20]; void update(int x, int l, int r, int aim, int w) { if (l == r) { node[x].first = w; node[x].second = l; return; } int mid = (l + r) >> 1; if (aim <= mid) update(x << 1, l, mid, aim, w); else update(x << 1 | 1, mid + 1, r, aim, w); if (node[x << 1].first >= node[x << 1 | 1].first) node[x] = node[x << 1]; else node[x] = node[x << 1 | 1]; } pair<int, int> que(int x, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) return node[x]; pair<int, int> ret = make_pair(0, 0); int mid = (l + r) >> 1; if (ql <= mid) ret = que(x << 1, l, mid, ql, qr); if (mid < qr) ret = max(ret, que(x << 1 | 1, mid + 1, r, ql, qr)); return ret; } void dfs(int x) { if (x <= n) { dfn[x] = ++tot_dfn; update(1, 1, n, dfn[x], p[x]); siz[x] = 1; V.push_back(x); } int mn = 1e9; for (auto y : e[x]) { dfs(y); siz[x] += siz[y]; mn = min(mn, dfn[y]); } if (x > n) dfn[x] = mn; } void solve(int x) { for (int i = ((int)(vec[x]).size()) - 1; i >= 0; i--) { auto pii = que(1, 1, n, dfn[x], dfn[x] + siz[x] - 1); ans[vec[x][i]] = pii.first; update(1, 1, n, pii.second, 0); } for (auto y : e[x]) { solve(y); } } int leader(int x) { return x == dsu[x] ? x : dsu[x] = leader(dsu[x]); } int main() { scanf("%d%d%d", &n, &m, &q); for (int i = 1; i <= n; i++) scanf("%d", &p[i]); for (int i = 1; i <= m; i++) scanf("%d%d", &E[i].first, &E[i].second); for (int i = 1; i <= q; i++) { scanf("%d%d", &query[i].first, &query[i].second); if (query[i].first == 2) vis[query[i].second] = true; } for (int i = 1; i <= n + q; i++) dsu[i] = i; tot = n; for (int i = 1; i <= m; i++) { if (vis[i]) continue; int s = leader(E[i].first), t = leader(E[i].second); if (s == t) continue; ++tot; dsu[s] = tot; dsu[t] = tot; dsu[tot] = tot; e[tot].push_back(s); e[tot].push_back(t); } for (int i = q; i > 0; i--) { if (query[i].first == 1) { int s = leader(query[i].second); vec[s].push_back(i); } else { int id = query[i].second; int s = leader(E[id].first), t = leader(E[id].second); if (s == t) continue; else { ++tot; dsu[s] = dsu[t] = tot; e[tot].push_back(s); e[tot].push_back(t); } } } for (int i = 1; i <= n; i++) Set.insert(leader(i)); for (auto x : Set) { dfs(x); solve(x); for (auto y : V) update(1, 1, n, y, 0); V.clear(); tot_dfn = 0; } for (int i = 1; i <= q; i++) if (query[i].first == 1) printf("%d\n", ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> ostream &operator<<(ostream &os, vector<T> V) { os << "[ "; for (auto v : V) os << v << " "; os << "]"; return os; } template <class T> ostream &operator<<(ostream &os, set<T> S) { os << "{ "; for (auto s : S) os << s << " "; return os << "}"; } template <class L, class R> ostream &operator<<(ostream &os, map<L, R> M) { os << "{ "; for (auto m : M) os << "(" << m.first << ":" << m.second << ") "; return os << "}"; } template <class L, class R> ostream &operator<<(ostream &os, pair<L, R> P) { return os << "(" << P.first << "," << P.second << ")"; } const long long N = 200005; long long p[N]; long long x[N << 1], y[N << 1]; bool removed[N << 1]; vector<pair<long long, long long>> query; struct DSU { vector<long long> a, s; vector<pair<long long, long long>> changes; vector<set<long long>> elements; DSU(long long n) { a.resize(n + 1); s.resize(n + 1); elements.resize(n + 1); for (int i = 1; i <= n; i++) { a[i] = i; s[i] = 1; elements[i].insert(p[i]); } } long long root(long long i) { while (i != a[i]) { i = a[i]; } return i; } bool merge(long long x, long long y) { long long xr = root(x), yr = root(y); if (xr == yr) { changes.push_back({xr, xr}); return false; } if (s[xr] < s[yr]) swap(xr, yr); s[xr] += s[yr]; elements[xr].insert(elements[yr].begin(), elements[yr].end()); a[yr] = xr; changes.push_back({xr, yr}); return true; } void rollBack() { if (changes.empty()) return; pair<long long, long long> p = changes.back(); long long xr = p.first, yr = p.second; changes.pop_back(); if (xr == yr) return; for (auto it = elements[yr].begin(); it != elements[yr].end();) { if (elements[xr].find(*it) != elements[xr].end()) elements[xr].erase(*it), it++; else it = elements[yr].erase(it); } a[yr] = yr; s[xr] = elements[xr].size(); s[yr] = elements[yr].size(); } long long query(long long x) { long long xr = root(x); if (elements[xr].empty()) return 0; long long ret = *(--elements[xr].end()); elements[xr].erase(--elements[xr].end()); s[xr]--; return ret; } }; int main() { ios_base::sync_with_stdio(false); cin.tie(NULL); set<long long> s; s.erase(5); long long n, m, q; cin >> n >> m >> q; for (long long i = 1; i < n + 1; i++) cin >> p[i]; for (long long i = 1; i < m + 1; i++) cin >> x[i] >> y[i]; query.resize(q); vector<long long> r; for (long long i = 0; i < q; i++) { cin >> query[i].first >> query[i].second; if (query[i].first == 2) removed[query[i].second] = true, r.push_back(query[i].second); } DSU d(n); for (long long i = 1; i < m + 1; i++) { if (!removed[i]) d.merge(x[i], y[i]); } reverse(r.begin(), r.end()); for (long long i = 0; i < r.size(); i++) d.merge(x[r[i]], y[r[i]]); for (long long i = 0; i < q; i++) { if (query[i].first == 1) cout << d.query(query[i].second) << '\n'; else d.rollBack(); } return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 5e5 + 10; const int maxm = 3e5 + 10; pair<int, int> Edge[maxm]; pair<int, int> Q[maxn]; vector<int> vec[maxn]; int arr[maxn], vis[maxm]; int n, m, q; int rnk[maxn], f[maxn]; int in[maxn], out[maxn], tot; int ufind(int x) { return x == f[x] ? x : f[x] = ufind(f[x]); } void uni(int u, int v) { int fu = ufind(u), fv = ufind(v); if (fu == fv) return; ++n; f[n] = n; f[fu] = f[fv] = n; vec[n].push_back(fu); vec[n].push_back(fv); } void dfs(int u) { in[u] = ++tot; for (auto& v : vec[u]) dfs(v); out[u] = tot; return; } int tree[maxn * 4]; void update(int o, int L, int R, int pos, int v) { int lch = o * 2, rch = o * 2 + 1; if (L == R) { tree[o] = v; return; } int mid = (L + R) / 2; if (pos <= mid) update(lch, L, mid, pos, v); else update(rch, mid + 1, R, pos, v); tree[o] = max(tree[lch], tree[rch]); return; } int query(int o, int L, int R, int l, int r) { int lch = o * 2, rch = o * 2 + 1; if (l <= L && R <= r) { return tree[o]; } int mid = (L + R) / 2; int ret = 0; if (l <= mid) ret = max(ret, query(lch, L, mid, l, r)); if (r > mid) ret = max(ret, query(rch, mid + 1, R, l, r)); return ret; } int main() { scanf("%d%d%d", &n, &m, &q); for (int i = 1; i <= n; i++) { scanf("%d", &arr[i]); rnk[arr[i]] = i; } for (int i = 1; i <= n; i++) f[i] = i; for (int i = 1; i <= m; i++) { scanf("%d%d", &Edge[i].first, &Edge[i].second); } for (int i = 1; i <= q; i++) { scanf("%d%d", &Q[i].first, &Q[i].second); if (Q[i].first == 2) vis[Q[i].second] = 1; } for (int i = 1; i <= m; i++) if (!vis[i]) uni(Edge[i].first, Edge[i].second); for (int i = q; i >= 1; i--) { if (Q[i].first == 1) Q[i].second = ufind(Q[i].second); else uni(Edge[Q[i].second].first, Edge[Q[i].second].second); } for (int i = 1; i <= n; i++) if (ufind(i) == i) dfs(i); for (int i = 1; i <= n; i++) update(1, 1, n, in[i], arr[i]); for (int i = 1; i <= q; i++) { if (Q[i].first == 1) { int x = query(1, 1, n, in[Q[i].second], out[Q[i].second]); printf("%d\n", x); if (x) update(1, 1, n, in[rnk[x]], 0); } } return 0; }
#include <bits/stdc++.h> using namespace std; int n, m, q; int A[1000006]; int fa[1000006], tot = 0; int find(int x) { return x == fa[x] ? x : fa[x] = find(fa[x]); } struct ed { int u, v, w; } E[1000006]; vector<pair<int, int> > qs; vector<int> G[1000006]; int que[1000006]; int L[1000006], R[1000006], bac[1000006], clo; void dfs(int u) { L[u] = ++clo, bac[clo] = u; for (int v : G[u]) dfs(v); R[u] = clo; } pair<int, int> T[1000006 << 2]; void pu(int rt) { T[rt] = max(T[rt << 1], T[rt << 1 | 1]); } void build(int rt, int l, int r) { if (l == r) { T[rt] = make_pair(A[bac[l]], l); return; } int m = l + r >> 1; build(rt << 1, l, m), build(rt << 1 | 1, m + 1, r); pu(rt); } pair<int, int> query(int rt, int l, int r, int L, int R) { if (L <= l && R >= r) return T[rt]; int m = l + r >> 1; pair<int, int> res; if (L <= m) res = max(res, query(rt << 1, l, m, L, R)); if (R > m) res = max(res, query(rt << 1 | 1, m + 1, r, L, R)); return res; } void mdfy(int rt, int l, int r, int p) { if (l == r) { T[rt] = {0, l}; return; } int m = l + r >> 1; if (p <= m) mdfy(rt << 1, l, m, p); else mdfy(rt << 1 | 1, m + 1, r, p); pu(rt); } void solve() { cin >> n >> m >> q; for (int i = (1), iend = (n); i <= iend; ++i) scanf("%d", A + i); for (int i = (1), iend = (n << 1); i <= iend; ++i) fa[i] = i; for (int i = (1), iend = (m); i <= iend; ++i) { static int u, v; scanf("%d%d", &u, &v); E[i] = (ed){u, v, 0x3f3f3f3f}; } for (int i = (1), iend = (q); i <= iend; ++i) { static int op, x; scanf("%d%d", &op, &x); if (op == 1) { qs.emplace_back(make_pair(x, i)); } else { E[x].w = i; } } sort(E + 1, E + 1 + m, [](ed a, ed b) { return a.w > b.w; }); sort((qs).begin(), (qs).end(), [](pair<int, int> a, pair<int, int> b) { return a.second > b.second; }); int u, v, cur = 0; tot = n; for (int i = (1), iend = (m); i <= iend; ++i) { u = find(E[i].u), v = find(E[i].v); while (qs[cur].second > E[i].w && cur < qs.size()) { que[qs[cur].second] = find(qs[cur].first); ++cur; } if (u != v) { fa[u] = fa[v] = ++tot; G[tot].push_back(u), G[tot].push_back(v); } } while (cur < qs.size()) que[qs[cur].second] = find(qs[cur].first), ++cur; for (int i = (1), iend = (tot); i <= iend; ++i) if (fa[i] == i) dfs(i); build(1, 1, tot); for (int i = (1), iend = (q); i <= iend; ++i) if (que[i]) { pair<int, int> as = query(1, 1, tot, L[que[i]], R[que[i]]); printf("%d\n", as.first); mdfy(1, 1, tot, as.second); } } signed main() { solve(); }
#include <bits/stdc++.h> using namespace std; template <typename T1, typename T2> string print_iterable(T1 begin_iter, T2 end_iter, int counter) { bool done_something = false; stringstream res; res << "["; for (; begin_iter != end_iter and counter; ++begin_iter) { done_something = true; counter--; res << *begin_iter << ", "; } string str = res.str(); if (done_something) { str.pop_back(); str.pop_back(); } str += "]"; return str; } vector<int> SortIndex(int size, std::function<bool(int, int)> compare) { vector<int> ord(size); for (int i = 0; i < size; i++) ord[i] = i; sort(ord.begin(), ord.end(), compare); return ord; } template <typename T> bool MinPlace(T& a, const T& b) { if (a > b) { a = b; return true; } return false; } template <typename T> bool MaxPlace(T& a, const T& b) { if (a < b) { a = b; return true; } return false; } template <typename S, typename T> ostream& operator<<(ostream& out, const pair<S, T>& p) { out << "{" << p.first << ", " << p.second << "}"; return out; } template <typename T> ostream& operator<<(ostream& out, const vector<T>& v) { out << "["; for (int i = 0; i < (int)v.size(); i++) { out << v[i]; if (i != (int)v.size() - 1) out << ", "; } out << "]"; return out; } template <class TH> void _dbg(const char* name, TH val) { clog << name << ": " << val << endl; } template <class TH, class... TA> void _dbg(const char* names, TH curr_val, TA... vals) { while (*names != ',') clog << *names++; clog << ": " << curr_val << ", "; _dbg(names + 1, vals...); } struct Edge { int u, v, id; int t; }; int N, Q; const int MAXN = 1 << 19; int dep[MAXN]; vector<int> aa[MAXN]; vector<int> ids[MAXN]; Edge edges[MAXN]; int queries[MAXN]; vector<int> prequery; void dfs(int v, int p) { for (int a : aa[v]) { if (a == p) continue; dep[a] = dep[v] + 1; dfs(a, v); } } int from[MAXN]; int to[MAXN]; int cnt; int dist[MAXN]; int ff0[2 * MAXN], ff1[2 * MAXN]; void preproc(int v, int p) { cnt++; int id = cnt; ff0[MAXN + id] = dist[v]; for (int i = 0; i < ((int)((aa[v]).size())); i++) { int a = aa[v][i]; if (a == p) continue; dist[a] = dist[v] + 1; from[ids[v][i]] = cnt + 1; preproc(a, v); to[ids[v][i]] = cnt; } } bool flag[2 * MAXN]; void f(int v, int l, int r, int a, int b) { if (a <= l and r <= b) { swap(ff0[v], ff1[v]); flag[v] ^= 1; return; } if (r < a or b < l) return; if (flag[v]) { flag[v] = false; swap(ff0[2 * v], ff1[2 * v]); swap(ff0[2 * v + 1], ff1[2 * v + 1]); flag[2 * v] ^= 1, flag[2 * v + 1] ^= 1; } int m = (l + r) / 2; f(2 * v, l, m, a, b); f(2 * v + 1, m + 1, r, a, b); ff0[v] = max(ff0[2 * v], ff0[2 * v + 1]); ff1[v] = max(ff1[2 * v], ff1[2 * v + 1]); } void process(int x) { f(1, 0, MAXN - 1, from[x], to[x]); } vector<int> solve(int root) { dist[root] = 0; cnt = 0; for (int i = 1; i < 2 * MAXN; i++) ff0[i] = ff1[i] = 0, flag[i] = false; preproc(root, -1); for (int i = MAXN - 1; i >= 1; i--) { ff0[i] = max(ff0[2 * i], ff0[2 * i + 1]); } for (int q : prequery) process(q); vector<int> ans(Q); for (int q = 0; q < Q; q++) { process(queries[q]); ans[q] = ff0[1]; } return ans; } int main() { ios::sync_with_stdio(false); cin.tie(0); cin >> N; for (int i = 0; i < N - 1; i++) { int u, v, t; cin >> u >> v >> t; aa[u].push_back(v); aa[v].push_back(u); ids[u].push_back(i + 1); ids[v].push_back(i + 1); if (t) prequery.push_back(i + 1); } dfs(1, 0); int A = 1; for (int v = 2; v <= N; v++) if (dep[v] > dep[A]) A = v; dep[A] = 0; dfs(A, 0); int B = 1; for (int v = 2; v <= N; v++) if (dep[v] > dep[B]) B = v; cin >> Q; for (int i = 0; i < Q; i++) cin >> queries[i]; vector<int> ans1 = solve(A); vector<int> ans2 = solve(B); for (int i = 0; i < Q; i++) cout << max(ans1[i], ans2[i]) << "\n"; }
#include <bits/stdc++.h> using namespace std; const int N = 5e5 + 99; int n, m, c, rt, fa, q[N], ans[N], h[N], a[N], s[N], t[N], w[N], edge[N][2]; vector<pair<int, int> > g[N]; int lazy[4 * N]; pair<int, int> seg[4 * N]; void shift(int, int, int); void build(int id = 1, int L = 1, int R = n + 1) { if (R <= L) return; if (L + 1 == R) { seg[id].second = 0; seg[id].first = h[a[L]]; if (w[a[L]]) swap(seg[id].first, seg[id].second); return; } int mid = (L + R + 1) >> 1; build(id * 2 + 0, L, mid); build(id * 2 + 1, mid, R); seg[id].first = max(seg[id * 2 + 0].first, seg[id * 2 + 1].first); seg[id].second = max(seg[id * 2 + 0].second, seg[id * 2 + 1].second); } void swich(int id, int L, int R, int l, int r) { if (R <= l || r <= L) return; if (l <= L && R <= r) { lazy[id] ^= 1; swap(seg[id].first, seg[id].second); return; } int mid = (L + R + 1) >> 1; shift(id, L, R); swich(id * 2 + 0, L, mid, l, r); swich(id * 2 + 1, mid, R, l, r); seg[id].first = max(seg[id * 2 + 0].first, seg[id * 2 + 1].first); seg[id].second = max(seg[id * 2 + 0].second, seg[id * 2 + 1].second); } void shift(int id, int L, int R) { int mid = (L + R + 1) >> 1; if (lazy[id] == 0) return; swich(id * 2 + 0, L, mid, L, mid); swich(id * 2 + 1, mid, R, mid, R); lazy[id] = 0; } void dfs1(int x, int dist, int par = 0) { if (fa < dist) fa = dist, rt = x; for (int i = 0; i < g[x].size(); i++) if (g[x][i].first != par) dfs1(g[x][i].first, dist + 1, x); } void dfs2(int x, int dist, int par, int second) { h[x] = dist; a[++c] = x; s[x] = c; for (int i = 0; i < g[x].size(); i++) if (g[x][i].first != par) dfs2(g[x][i].first, dist + 1, x, second ^ g[x][i].second); t[x] = c + 1; w[x] = second; } void solve(int rt) { for (int i = 0; i < 4 * N; i++) seg[i].first = seg[i].second = lazy[i] = 0; c = 0; dfs2(rt, 0, 0, 0); build(); for (int i = 0; i < m; i++) { int u; if (h[edge[q[i]][1]] < h[edge[q[i]][0]]) u = edge[q[i]][0]; else u = edge[q[i]][1]; swich(1, 1, n + 1, s[u], t[u]); ans[i] = max(ans[i], seg[1].first); ; } } int main() { cin >> n; for (int i = 1; i < n; i++) { int u, v, t; scanf("%d%d", &u, &v); ; scanf("%d", &t); ; edge[i][0] = u; edge[i][1] = v; g[u].push_back(make_pair(v, t)); g[v].push_back(make_pair(u, t)); } cin >> m; for (int i = 0; i < m; i++) cin >> q[i]; fa = 0; dfs1(1, 0); solve(rt); fa = 0; dfs1(rt, 0); solve(rt); for (int i = 0; i < m; i++) cout << ans[i] << '\n'; }
#include <bits/stdc++.h> using namespace std; int n; vector<pair<int, int> > v[500007]; pair<int, int> edge_list[500007]; int diam[2]; class Tree { int root; vector<int> ord; int st[500007], en[500007]; int rev[500007]; int depth[500007], parity[500007]; void dfs(int vertex, int prv) { ord.push_back(vertex); st[vertex] = ord.size(); rev[st[vertex]] = vertex; int sz = v[vertex].size(); for (int i = 0; i < sz; ++i) { int to, cost; to = v[vertex][i].first; cost = v[vertex][i].second; if (to == prv) { continue; } depth[to] = depth[vertex] + 1; parity[to] = parity[vertex] ^ cost; dfs(to, vertex); } en[vertex] = ord.size(); } int tr[4 * 500007][2]; int lazy[4 * 500007]; void unite(int where) { for (int i = 0; i < 2; ++i) { tr[where][i] = max(tr[2 * where][i], tr[2 * where + 1][i]); } } void init_segtree(int where, int IL, int IR) { lazy[where] = 0; if (IL == IR) { int x = rev[IL]; tr[where][parity[x]] = depth[x]; tr[where][parity[x] ^ 1] = 0; return; } int mid = (IL + IR) / 2; init_segtree(2 * where, IL, mid); init_segtree(2 * where + 1, mid + 1, IR); unite(where); } void push_lazy(int where, int IL, int IR) { if (lazy[where] == 0) { return; } swap(tr[where][0], tr[where][1]); if (IL != IR) { lazy[2 * where] ^= 1; lazy[2 * where + 1] ^= 1; } lazy[where] = 0; } void update(int where, int IL, int IR, int CURL, int CURR) { push_lazy(where, IL, IR); if (IL > IR || CURL > CURR) { return; } if (CURR < IL || IR < CURL) { return; } if (CURL <= IL && IR <= CURR) { lazy[where] ^= 1; push_lazy(where, IL, IR); return; } int mid = (IL + IR) / 2; update(2 * where, IL, mid, CURL, CURR); update(2 * where + 1, mid + 1, IR, CURL, CURR); unite(where); } public: void init(int _root) { root = _root; depth[root] = parity[root] = 0; ord.clear(); dfs(root, -1); init_segtree(1, 1, n); } void handle(int id) { int x = edge_list[id].first; int y = edge_list[id].second; if (st[x] < st[y]) { swap(x, y); } update(1, 1, n, st[x], en[x]); } int query() { return tr[1][0]; } }; Tree w[2]; int len[500007]; int bfs(int ori) { for (int i = 1; i <= n; ++i) { len[i] = 500007; } len[ori] = 0; queue<int> q; q.push(ori); while (q.empty() == false) { int x = q.front(); q.pop(); int sz = v[x].size(); for (int i = 0; i < sz; ++i) { int to = v[x][i].first; if (len[to] == 500007) { len[to] = len[x] + 1; q.push(to); } } } int mx, id; mx = id = 0; for (int i = 1; i <= n; ++i) { if (mx < len[i]) { mx = len[i]; id = i; } } return id; } void input() { scanf("%d", &n); for (int i = 1; i < n; ++i) { int x, y, z; scanf("%d%d%d", &x, &y, &z); v[x].push_back({y, z}); v[y].push_back({x, z}); edge_list[i] = {x, y}; } diam[0] = bfs(1); diam[1] = bfs(diam[0]); } void solve() { for (int i = 0; i < 2; ++i) { w[i].init(diam[i]); } int q; scanf("%d", &q); while (q--) { int x; scanf("%d", &x); w[0].handle(x); w[1].handle(x); printf("%d\n", max(w[0].query(), w[1].query())); } } int main() { ios_base ::sync_with_stdio(false); cin.tie(NULL); input(); solve(); return 0; }
#include <bits/stdc++.h> using std::swap; template <typename T> T& setmax(T& a, const T& b) { if (b > a) a = b; return a; } template <typename T> T& setmin(T& a, const T& b) { if (b < a) a = b; return a; } const int INF = 1e9; struct top_tree_node { mutable top_tree_node* p = nullptr; top_tree_node* c[3] = {nullptr, nullptr, nullptr}; int d() const { assert(p); if (this == p->c[0]) { return 0; } else if (this == p->c[1]) { return 1; } else if (this == p->c[2]) { return 2; } else assert(false); } top_tree_node*& p_c() const { return p->c[d()]; } bool is_path; bool is_vert; bool r() const { return !p || p->is_path != is_path; } bool flip_path = false; bool own_parity; int path_len; bool path_parity; int best_path; std::array<int, 2> best_up; std::array<int, 2> best_down; void do_flip_path() { assert(is_path); flip_path ^= 1; swap(best_up, best_down); } void do_flip_edge_parity() { assert(!is_vert); own_parity ^= 1; update(); } void downdate() { if (flip_path) { assert(is_path); if (!is_vert) { if (c[0]) c[0]->do_flip_path(); if (c[1]) c[1]->do_flip_path(); } swap(c[0], c[1]); flip_path = false; } } void update() { if (is_path && !is_vert) { assert(!c[2]); assert(c[0] && c[1]); path_len = c[0]->path_len + 1 + c[1]->path_len; path_parity = c[0]->path_parity ^ own_parity ^ c[1]->path_parity; best_up = c[0]->best_up; for (int z = 0; z < 2; z++) { setmax(best_up[c[0]->path_parity ^ own_parity ^ z], c[0]->path_len + 1 + c[1]->best_up[z]); } best_down = c[1]->best_down; for (int z = 0; z < 2; z++) { setmax(best_down[c[1]->path_parity ^ own_parity ^ z], c[1]->path_len + 1 + c[0]->best_down[z]); } best_path = std::max(c[0]->best_path, c[1]->best_path); for (int z = 0; z < 2; z++) { setmax(best_path, c[0]->best_down[z] + 1 + c[1]->best_up[z ^ own_parity]); } } else { assert((is_vert && is_path) || (!is_vert && !is_path)); if (is_vert) { path_len = 0; path_parity = 0; best_path = 0; best_up = {0, -INF}; } else { best_path = c[2]->best_path; best_up = c[2]->best_up; if (own_parity) { swap(best_up[0], best_up[1]); } best_up[0]++, best_up[1]++; } for (int d = 0; d < 2; d++) { if (!c[d]) continue; setmax(best_path, c[d]->best_path); for (int z = 0; z < 2; z++) { setmax(best_path, c[d]->best_up[z] + best_up[z]); setmax(best_up[z], c[d]->best_up[z]); } } best_down = best_up; } if (flip_path) { assert(is_path); swap(best_up, best_down); } } void downdate_all() { if (p) p->downdate_all(); downdate(); } void update_all() { update(); if (p) p->update_all(); } private: void rot() { assert(!is_vert); assert(!r()); top_tree_node* pa = p; int x = d(); assert(x == 0 || x == 1); top_tree_node* ch = c[!x]; if (pa->p) pa->p_c() = this; this->p = pa->p; pa->c[x] = ch; if (ch) ch->p = pa; this->c[!x] = pa; pa->p = this; pa->update(); } void rot_2(int c_d) { assert(!is_vert); assert(!r()); assert(c[c_d]); assert(!c[c_d]->is_vert); if (d() == c_d) { rot(); return; } top_tree_node* pa = p; int x = d(); assert(x == 0 || x == 1); assert(c_d == !x); top_tree_node* ch = c[c_d]->c[!x]; if (pa->p) pa->p_c() = this; this->p = pa->p; pa->c[x] = ch; if (ch) ch->p = pa; this->c[c_d]->c[!x] = pa; pa->p = this->c[c_d]; pa->update(); } void splay_dir(int x) { while (!r() && d() == x) { if (!p->r() && p->d() == x) { p->rot(); } rot(); } } void splay_2(int c_d) { assert(!is_vert && is_path); assert(c[c_d] && !c[c_d]->is_vert); while (!r()) { if (!p->r()) { if (p->d() == d()) { p->rot(); } else { rot_2(c_d); } } rot_2(c_d); } } void splay_2() { assert(!is_vert && is_path); assert(!r()); p->splay_2(d()); } void splay_vert() { assert(is_vert); if (r()) { return; } p->splay_dir(d()); if (p->r()) { return; } assert(p->d() != d()); if (d() == 1) { p->rot(); } assert(d() == 0); p->splay_2(); assert(d() == 0); assert(p->d() == 1); assert(p->p->r()); } void splay() { assert(!is_vert); while (!r()) { if (!p->r()) { if (p->d() == d()) { p->rot(); } else { rot(); } } rot(); } } top_tree_node* cut_right() { assert(is_vert && is_path); splay_vert(); if (r() || d() == 1) { assert(r() || (d() == 1 && p->r())); assert(c[0] == nullptr); return nullptr; } top_tree_node* pa = p; assert(pa->r() || (pa->d() == 1 && pa->p->r())); assert(!pa->is_vert); assert(pa->is_path); assert(pa->c[0] == this); assert(pa->c[2] == nullptr); if (pa->p) pa->p_c() = this; this->p = pa->p; pa->is_path = false; pa->c[2] = pa->c[1]; pa->c[0] = c[0]; if (c[0]) c[0]->p = pa; pa->c[1] = c[1]; if (c[1]) c[1]->p = pa; c[0] = nullptr; c[1] = pa; pa->p = this; assert(c[2] == nullptr); assert(c[0] == nullptr); pa->update(); return pa; } top_tree_node* splice_non_path() { assert(!is_path); assert(!is_vert); splay(); assert(p && p->is_vert && p->is_path); p->cut_right(); if (!p->is_path) rot(); assert(p && p->is_vert && p->is_path); assert(p->r() || (p->d() == 1 && p->p->r())); assert(p->c[d()] == this && p->c[!d()] == nullptr); top_tree_node* pa = p; if (pa->p) pa->p_c() = this; this->p = pa->p; pa->c[0] = c[0]; if (c[0]) c[0]->p = pa; pa->c[1] = c[1]; if (c[1]) c[1]->p = pa; assert(c[2] && c[2]->is_path); c[1] = c[2]; c[0] = pa; pa->p = this; c[2] = nullptr; is_path = true; pa->update(); return pa; } void splice_all(top_tree_node*& res) { if (!is_path) { res = splice_non_path(); } assert(is_path); if (!p) return; p->splice_all(res); } public: top_tree_node* expose() { assert(is_vert); downdate_all(); top_tree_node* res = nullptr; splice_all(res); cut_right(); update_all(); return res; } void meld_path_end() { assert(!p); top_tree_node* rt = this; while (true) { rt->downdate(); if (rt->is_vert) break; rt = rt->c[1]; } assert(rt->is_vert); rt->splay_vert(); if (rt->c[0] && rt->c[1]) { top_tree_node* ch = rt->c[1]; while (true) { ch->downdate(); if (!ch->c[0]) break; ch = ch->c[0]; } ch->splay(); assert(ch->c[0] == nullptr); ch->c[0] = rt->c[0]; ch->c[0]->p = ch; rt->c[0] = nullptr; ch->update(); } else if (rt->c[0]) { rt->c[1] = rt->c[0]; rt->c[0] = nullptr; } assert(rt->c[0] == nullptr); rt->update_all(); } void make_root() { expose(); top_tree_node* rt = this; while (rt->p) { assert(rt->d() == 1); rt = rt->p; } rt->do_flip_path(); rt->meld_path_end(); expose(); assert(!p); } friend void link(top_tree_node* e, top_tree_node* v1, top_tree_node* v2) { assert(e && v1 && v2); assert(!e->c[0] && !e->c[1] && !e->c[2]); v1->expose(); while (v1->p) v1 = v1->p; v2->make_root(); assert(!v1->p); assert(!v2->p); e->is_path = true, e->is_vert = false; e->c[0] = v1; v1->p = e; e->c[1] = v2; v2->p = e; e->update(); } friend std::pair<top_tree_node*, top_tree_node*> cut(top_tree_node* e) { assert(!e->p); assert(e->is_path); assert(!e->is_vert); e->downdate(); top_tree_node* l = e->c[0]; top_tree_node* r = e->c[1]; assert(l && r); e->c[0] = e->c[1] = nullptr; l->p = r->p = nullptr; assert(e->c[2] == nullptr); l->meld_path_end(); return {l, r}; } friend top_tree_node* get_path(top_tree_node* a, top_tree_node* b) { assert(a->is_vert && b->is_vert); a->make_root(); b->expose(); if (a == b) { assert(!b->p); return b; } assert(!b->p->p); return b->p; } friend top_tree_node* get_subtree(top_tree_node* rt, top_tree_node* n) { rt->make_root(); n->expose(); return n; } }; int main() { using namespace std; ios_base::sync_with_stdio(false), cin.tie(nullptr); int N; cin >> N; vector<top_tree_node> nodes(N + (N - 1)); for (int i = 0; i < N; i++) { top_tree_node* n = &nodes[i]; n->is_path = n->is_vert = true; n->update(); } vector<array<int, 2>> edges(N - 1); for (int e = 0; e < N - 1; e++) { int u, v, t; cin >> u >> v >> t; u--, v--; edges[e] = {u, v}; nodes[N + e].own_parity = t; link(&nodes[N + e], &nodes[u], &nodes[v]); } int Q; cin >> Q; while (Q--) { int e; cin >> e; e--; auto [u, v] = edges[e]; auto pth = get_path(&nodes[u], &nodes[v]); assert(pth == &nodes[N + e]); pth->do_flip_edge_parity(); cout << pth->best_path << '\n'; } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 555555; const int M = 1111111; const int MOD = 998244353; const int intINF = 1e9; const long long llINF = 2e18; const double pi = acos(-1.0); const int inv2 = 5e8 + 4; int read() { int v = 0, f = 1; char c = getchar(); while (c < 48 || 57 < c) { if (c == '-') f = -1; c = getchar(); } while (48 <= c && c <= 57) v = (v << 3) + v + v + c - 48, c = getchar(); return v * f; } long long readll() { long long v = 0, f = 1; char c = getchar(); while (c < 48 || 57 < c) { if (c == '-') f = -1; c = getchar(); } while (48 <= c && c <= 57) v = (v << 3) + v + v + c - 48, c = getchar(); return v * f; } unsigned long long readull() { long long v = 0, f = 1; char c = getchar(); while (c < 48 || 57 < c) { if (c == '-') f = -1; c = getchar(); } while (48 <= c && c <= 57) v = (v << 3) + v + v + c - 48, c = getchar(); return v * f; } void predo() {} int head[N], vet[M], len[M], nxt[M], tot, n; void add(int a, int b, int c) { nxt[++tot] = head[a]; vet[tot] = b; len[tot] = c; head[a] = tot; } struct edge { int x, y; } E[M]; void init() { n = read(); for (int i = (int)1; i <= (int)n - 1; i++) { int x = read(), y = read(), z = read(); add(x, y, z); add(y, x, z); E[i].x = x; E[i].y = y; } } int st[N], ed[N], dis[N], dep[N], id[N], tim; void dfs(int u, int fa) { st[u] = ++tim; id[tim] = u; int e = head[u]; while (e) { int v = vet[e]; if (v != fa) { dep[v] = dep[u] + 1; dis[v] = dis[u] ^ len[e]; dfs(v, u); } e = nxt[e]; } ed[u] = tim; } int ST[N][2], ED[N][2], d[N][2], dep1[N], dep2[N], r1, r2; struct seg_tree { struct node { int s[2], tag; } t[N << 2]; void pushup(int p) { t[p].s[0] = max(t[p << 1].s[0], t[p << 1 | 1].s[0]); t[p].s[1] = max(t[p << 1].s[1], t[p << 1 | 1].s[1]); } void pushdown(int p) { if (t[p].tag) { swap(t[p << 1].s[0], t[p << 1].s[1]); swap(t[p << 1 | 1].s[0], t[p << 1 | 1].s[1]); t[p << 1].tag ^= 1; t[p << 1 | 1].tag ^= 1; t[p].tag = 0; } } void update(int l, int r, int x, int y, int p) { if (x <= l && r <= y) { swap(t[p].s[0], t[p].s[1]); t[p].tag ^= 1; return; } pushdown(p); int mid = (l + r) >> 1; if (x <= mid) update(l, mid, x, y, p << 1); if (y > mid) update(mid + 1, r, x, y, p << 1 | 1); pushup(p); } } T1, T2; int id1[N], id2[N]; void build1(int l, int r, int p) { T1.t[p].s[0] = T1.t[p].s[1] = 0; T1.t[p].tag = 0; if (l == r) { if (id1[l]) T1.t[p].s[d[id1[l]][0]] = dep1[id1[l]]; return; } int mid = (l + r) >> 1; build1(l, mid, p << 1); build1(mid + 1, r, p << 1 | 1); T1.pushup(p); } void build2(int l, int r, int p) { T2.t[p].s[0] = T2.t[p].s[1] = 0; T2.t[p].tag = 0; if (l == r) { if (id2[l]) T2.t[p].s[d[id2[l]][1]] = dep2[id2[l]]; return; } int mid = (l + r) >> 1; build2(l, mid, p << 1); build2(mid + 1, r, p << 1 | 1); T2.pushup(p); } void solve() { tim = 0; dis[1] = dep[1] = 0; dfs(1, 0); int r1 = 1; for (int i = (int)1; i <= (int)n; i++) { if (dep[i] > dep[r1]) r1 = i; } tim = 0; dis[r1] = dep[r1] = 0; dfs(r1, 0); int r2 = 1; for (int i = (int)1; i <= (int)n; i++) { if (dep[i] > dep[r2]) r2 = i; } for (int i = (int)1; i <= (int)n; i++) { ST[i][0] = st[i]; ED[i][0] = ed[i]; d[i][0] = dis[i]; dep1[i] = dep[i]; id1[i] = id[i]; } tim = 0; dis[r2] = dep[r2] = 0; dfs(r2, 0); for (int i = (int)1; i <= (int)n; i++) { ST[i][1] = st[i]; ED[i][1] = ed[i]; d[i][1] = dis[i]; dep2[i] = dep[i]; id2[i] = id[i]; } build1(1, n, 1); build2(1, n, 1); int q = read(); while (q--) { int id = read(); int x = E[id].x, y = E[id].y; int u; if (dep1[x] > dep1[y]) u = x; else u = y; T1.update(1, n, ST[u][0], ED[u][0], 1); if (dep2[x] > dep2[y]) u = x; else u = y; T2.update(1, n, ST[u][1], ED[u][1], 1); int ans = 0; ans = max(ans, T1.t[1].s[0]); ans = max(ans, T2.t[1].s[0]); printf("%d\n", ans); } } int main() { predo(); int cas = 1; while (cas--) { init(); solve(); } return 0; }
#include <bits/stdc++.h> using namespace std; template <typename T> void debug_out(T t) { cerr << t; } template <typename A, typename B> void debug_out(pair<A, B> u) { cerr << "(" << u.first << " " << u.second << ")"; } template <typename T> void debug_out(vector<T> t) { int sz = t.size(); for (int i = 0; i < sz; i++) { debug_out(t[i]); if (i != sz - 1) cerr << ", "; } } template <typename T> void debug_out(vector<vector<T>> t) { int sz = t.size(); for (int i = 0; i < sz; i++) { debug_out(t[i]); if (i != sz - 1) cerr << endl; } } template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) { debug_out(H); cerr << " "; debug_out(T...); } template <typename T> void debug_out(set<T> a) { vector<T> _a; for (T t : a) _a.push_back(t); debug_out(_a); } class segtree { public: struct node { int black = INT_MIN; int white = INT_MIN; bool exchange = false; void apply(int l, int r, int v) { if (v >= 0) { int t = v & 1; v >>= 1; if (t) black = v; else white = v; } else { swap(black, white); exchange ^= true; } } }; node unite(const node &a, const node &b) const { node res; res.black = max(a.black, b.black); res.white = max(a.white, b.white); return res; } inline void push(int x, int l, int r) { int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); if (tree[x].exchange) { tree[x + 1].apply(l, y, -1); tree[z].apply(y + 1, r, -1); tree[x].exchange = false; } } inline void pull(int x, int z) { tree[x] = unite(tree[x + 1], tree[z]); } int n; vector<node> tree; void build(int x, int l, int r) { if (l == r) { return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); build(x + 1, l, y); build(z, y + 1, r); pull(x, z); } template <typename M, typename... T> void build(int x, int l, int r, const vector<M> &v, const T &...t) { if (l == r) { tree[x].apply(l, r, v[l], t...); return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); build(x + 1, l, y, v, t...); build(z, y + 1, r, v, t...); pull(x, z); } template <typename M, typename... T> segtree(const vector<M> &v, const T &...t) { n = v.size(); assert(n > 0); tree.resize(2 * n - 1); build(0, 0, n - 1, v, t...); } segtree(int _n) : n(_n) { assert(n > 0); tree.resize(2 * n - 1); build(0, 0, n - 1); } segtree(){}; node get(int x, int l, int r, int ll, int rr) { if (ll <= l && r <= rr) { return tree[x]; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); push(x, l, r); node res{}; if (rr <= y) { res = get(x + 1, l, y, ll, rr); } else { if (ll > y) { res = get(z, y + 1, r, ll, rr); } else { res = unite(get(x + 1, l, y, ll, rr), get(z, y + 1, r, ll, rr)); } } pull(x, z); return res; } node get(int ll, int rr) { assert(0 <= ll && ll <= rr && rr <= n - 1); return get(0, 0, n - 1, ll, rr); } node get(int p) { assert(0 <= p && p <= n - 1); return get(0, 0, n - 1, p, p); } template <typename... M> void modify(int x, int l, int r, int ll, int rr, const M &...v) { if (ll <= l && r <= rr) { tree[x].apply(l, r, v...); return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); push(x, l, r); if (ll <= y) { modify(x + 1, l, y, ll, rr, v...); } if (rr > y) { modify(z, y + 1, r, ll, rr, v...); } pull(x, z); } template <typename... M> void modify(int ll, int rr, const M &...v) { assert(0 <= ll && ll <= rr && rr <= n - 1); modify(0, 0, n - 1, ll, rr, v...); } }; int n; int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n; vector<vector<int>> g(n); vector<int> from(n - 1); vector<int> to(n - 1); vector<int> d(n - 1); for (int i = 0; i < n - 1; i++) { int u, v, t; cin >> u >> v >> t; u--; v--; g[u].push_back(i); g[v].push_back(i); from[i] = u; to[i] = v; d[i] = t; } vector<int> dep(n); function<void(int, int)> dfs0 = [&](int v, int p) { if (~p) dep[v] = dep[p] + 1; else dep[v] = 0; for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs0(id, v); } }; dfs0(0, -1); int left_root = max_element(dep.begin(), dep.end()) - dep.begin(); dfs0(left_root, -1); int right_root = max_element(dep.begin(), dep.end()) - dep.begin(); vector<int> order; vector<int> din(n); vector<int> dout(n); vector<int> par(n); function<void(int, int)> dfs = [&](int v, int p) { par[v] = p; if (~p) dep[v] = dep[p] + 1; else dep[v] = 0; din[v] = order.size(); order.push_back(v); for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs(id, v); } dout[v] = order.size() - 1; }; vector<int> R_order, R_in, R_out, R_dep, R_par, L_order, L_in, L_out, L_dep, L_par; dfs(right_root, -1); R_order = order; R_in = din; R_out = dout; R_dep = dep; R_par = par; order.clear(); dfs(left_root, -1); L_order = order; L_in = din; L_out = dout; L_dep = dep; L_par = par; vector<int> pos(n); function<void(int, int, int)> dfs1 = [&](int v, int p, int t) { pos[v] = t; for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs1(id, v, t ^ d[i]); } }; dfs1(0, -1, 0); for (int i = 0; i < n; i++) { L_dep[i] = L_dep[i] * 2 + pos[i]; R_dep[i] = R_dep[i] * 2 + pos[i]; } for (int i = 0; i < n; i++) { L_order[i] = L_dep[L_order[i]]; R_order[i] = R_dep[R_order[i]]; } segtree Lst(L_order); segtree Rst(R_order); int q; cin >> q; while (q--) { int id; cin >> id; id--; int u = from[id]; int v = to[id]; int ret = 0; { if (L_par[v] == u) swap(u, v); Lst.modify(L_in[u], L_out[u], -1); segtree::node x = Lst.get(0, n - 1); int cc = pos[left_root] ? x.black : x.white; ret = max(ret, cc); } { if (R_par[v] == u) swap(u, v); Rst.modify(R_in[u], R_out[u], -1); segtree::node x = Rst.get(0, n - 1); int cc = pos[right_root] ? x.black : x.white; ret = max(ret, cc); } cout << ret << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; const int SZ = 1 << 19; vector<pair<int, int>> adj[500000]; pair<int, int> E[500000]; int node_cnt, num[500000], R[500000], parent[500000], depth[500000], tree[2 * SZ][3], Q[500000], ans[500000]; void lazy_propagation(int bit, int s, int e) { if (tree[bit][2]) { swap(tree[bit][0], tree[bit][1]); if (s < e) { tree[2 * bit][2] ^= 1; tree[2 * bit + 1][2] ^= 1; } tree[bit][2] = 0; } } int bfs(int c) { queue<int> Q; memset(depth, -1, sizeof(depth)); depth[c] = 0; Q.push(c); while (!Q.empty()) { c = Q.front(); Q.pop(); for (auto [n, w] : adj[c]) if (depth[n] == -1) { depth[n] = depth[c] + 1; Q.push(n); } } return c; } void dfs(int c, int v) { num[c] = ++node_cnt; tree[SZ + num[c]][v] = depth[c]; for (auto [n, w] : adj[c]) if (num[n] == 0) { parent[n] = c; depth[n] = depth[c] + 1; dfs(n, w ^ v); } R[c] = node_cnt; } void flip(int n1, int n2, int bit = 1, int s = 0, int e = SZ - 1) { int m = (s + e) >> 1; lazy_propagation(bit, s, e); if (n2 < n1 || n2 < s || e < n1) return; if (n1 <= s && e <= n2) { tree[bit][2] = 1; lazy_propagation(bit, s, e); return; } flip(n1, n2, 2 * bit, s, m); flip(n1, n2, 2 * bit + 1, m + 1, e); tree[bit][0] = max(tree[2 * bit][0], tree[2 * bit + 1][0]); tree[bit][1] = max(tree[2 * bit][1], tree[2 * bit + 1][1]); } int main() { ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); ((void)0); ((void)0); ((void)0); int N, M, r; cin >> N; for (int i = 1; i < N; i++) { int v; cin >> E[i].first >> E[i].second >> v; adj[--E[i].first].emplace_back(--E[i].second, v); adj[E[i].second].emplace_back(E[i].first, v); } r = bfs(0); depth[parent[r] = r] = 0; dfs(r, 0); for (int i = SZ; --i;) for (int j = 0; j < 2; j++) tree[i][j] = max(tree[2 * i][j], tree[2 * i + 1][j]); cin >> M; for (int c = 0; c < M; c++) { int i; cin >> Q[c]; if (parent[E[Q[c]].first] == E[Q[c]].second) i = E[Q[c]].first; else i = E[Q[c]].second; flip(num[i], R[i]); ans[c] = tree[1][0]; } r = bfs(r); memset(num, 0, sizeof(num)); memset(tree, 0, sizeof(tree)); node_cnt = depth[parent[r] = r] = 0; dfs(r, 0); for (int i = SZ; --i;) for (int j = 0; j < 2; j++) tree[i][j] = max(tree[2 * i][j], tree[2 * i + 1][j]); for (int c = 0; c < M; c++) { int i; if (parent[E[Q[c]].first] == E[Q[c]].second) i = E[Q[c]].first; else i = E[Q[c]].second; flip(num[i], R[i]); cout << max(ans[c], tree[1][0]) << '\n'; } return 0; }
#include <bits/stdc++.h> using namespace std; const int MX = 500005; tuple<int, int, int> edges[MX]; int queries[MX]; int ans[MX]; vector<pair<int, int>> neigh[MX]; int depth[MX]; int pos[MX]; int sz[MX]; int val[MX]; int order[MX]; void calc_depth(int v, int p, int d) { depth[v] = d; for (auto e : neigh[v]) { if (e.first == p) continue; calc_depth(e.first, v, d + 1); } } int cnt; void dfs(int v, int p, int s) { pos[v] = cnt; order[cnt] = v; sz[v] = 1; val[v] = s; cnt++; for (auto e : neigh[v]) { if (e.first == p) continue; dfs(e.first, v, (s + e.second) % 2); sz[v] += sz[e.first]; } } struct { int L, R; int pl, pr; int d0, d1, flip; } T[2 * MX]; int tsz; int buildTree(int L, int R) { int cur = tsz++; T[cur].L = L; T[cur].R = R; if (L < R) { T[cur].pl = buildTree(L, (L + R) / 2); T[cur].pr = buildTree((L + R) / 2 + 1, R); T[cur].d0 = max(T[T[cur].pl].d0, T[T[cur].pr].d0); T[cur].d1 = max(T[T[cur].pl].d1, T[T[cur].pr].d1); T[cur].flip = 0; } else { int v = order[L]; if (val[v] == 0) { T[cur].d0 = depth[v]; T[cur].d1 = 0; } else { T[cur].d0 = 0; T[cur].d1 = depth[v]; } T[cur].flip = 0; } return cur; } void update(int L, int R, int cur) { if (L <= T[cur].L && R >= T[cur].R) { swap(T[cur].d0, T[cur].d1); T[cur].flip ^= 1; return; } if (T[cur].flip) { swap(T[T[cur].pl].d0, T[T[cur].pl].d1); swap(T[T[cur].pr].d0, T[T[cur].pr].d1); T[T[cur].pl].flip ^= 1; T[T[cur].pr].flip ^= 1; T[cur].flip = 0; } if (L <= T[T[cur].pl].R) { update(L, R, T[cur].pl); } if (T[T[cur].pr].L <= R) { update(L, R, T[cur].pr); } T[cur].d0 = max(T[T[cur].pl].d0, T[T[cur].pr].d0); T[cur].d1 = max(T[T[cur].pl].d1, T[T[cur].pr].d1); } int n, m; void Solve(int root) { calc_depth(root, 0, 0); cnt = 0; dfs(root, 0, 0); tsz = 0; buildTree(1, n); for (int i = 0; i < m; i++) { int u, v; tie(u, v, ignore) = edges[queries[i]]; if (depth[u] > depth[v]) { swap(u, v); } int L = pos[v]; int R = pos[v] + sz[v] - 1; update(L, R, 0); ans[i] = max(ans[i], T[0].d0); } } int main() { ios::sync_with_stdio(false); cin.tie(0); ignore = scanf("%d", &n); for (int i = 1; i <= n - 1; i++) { int u, v, t; ignore = scanf("%d %d %d", &u, &v, &t); edges[i] = tie(u, v, t); neigh[u].emplace_back(v, t); neigh[v].emplace_back(u, t); } int A = 1, B = 1; calc_depth(1, 0, 0); for (int v = 1; v <= n; v++) { if (depth[v] > depth[A]) A = v; } calc_depth(A, 0, 0); for (int v = 1; v <= n; v++) { if (depth[v] > depth[B]) B = v; } ignore = scanf("%d", &m); for (int i = 0; i < m; i++) { ignore = scanf("%d", &queries[i]); } Solve(A); Solve(B); for (int i = 0; i < m; i++) { printf("%d\n", ans[i]); } }
#include <bits/stdc++.h> using namespace std; const int inf = 1e9 + 9; const long long int MOD = 1e9 + 696969; mt19937_64 rng(time(0)); int random(int l, int r) { return uniform_int_distribution<int>(l, r)(rng); } const long long INF = 1e18; const int maxn = 500100; namespace atcoder { namespace internal { int ceil_pow2(int n) { int x = 0; while ((1U << x) < (unsigned int)(n)) x++; return x; } int bsf(unsigned int n) { return __builtin_ctz(n); } } // namespace internal } // namespace atcoder namespace atcoder { template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()> struct lazy_segtree { public: lazy_segtree() : lazy_segtree(0) {} lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {} lazy_segtree(const std::vector<S> &v) : _n(int(v.size())) { log = internal::ceil_pow2(_n); size = 1 << log; d = std::vector<S>(2 * size, e()); lz = std::vector<F>(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) { update(i); } } void set(int p, S x) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = x; for (int i = 1; i <= log; i++) update(p >> i); } S get(int p) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); return d[p]; } S prod(int l, int r) { assert(0 <= l && l <= r && r <= _n); if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push(r >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S all_prod() { return d[1]; } void apply(int p, F f) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = mapping(f, d[p]); for (int i = 1; i <= log; i++) update(p >> i); } void apply(int l, int r, F f) { assert(0 <= l && l <= r && r <= _n); if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } template <bool (*g)(S)> int max_right(int l) { return max_right(l, [](S x) { return g(x); }); } template <class G> int max_right(int l, G g) { assert(0 <= l && l <= _n); assert(g(e())); if (l == _n) return _n; l += size; for (int i = log; i >= 1; i--) push(l >> i); S sm = e(); do { while (l % 2 == 0) l >>= 1; if (!g(op(sm, d[l]))) { while (l < size) { push(l); l = (2 * l); if (g(op(sm, d[l]))) { sm = op(sm, d[l]); l++; } } return l - size; } sm = op(sm, d[l]); l++; } while ((l & -l) != l); return _n; } template <bool (*g)(S)> int min_left(int r) { return min_left(r, [](S x) { return g(x); }); } template <class G> int min_left(int r, G g) { assert(0 <= r && r <= _n); assert(g(e())); if (r == 0) return 0; r += size; for (int i = log; i >= 1; i--) push((r - 1) >> i); S sm = e(); do { r--; while (r > 1 && (r % 2)) r >>= 1; if (!g(op(d[r], sm))) { while (r < size) { push(r); r = (2 * r + 1); if (g(op(d[r], sm))) { sm = op(d[r], sm); r--; } } return r + 1 - size; } sm = op(d[r], sm); } while ((r & -r) != r); return 0; } private: int _n, size, log; std::vector<S> d; std::vector<F> lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; } // namespace atcoder using namespace atcoder; int n, d[maxn]; bool odw[maxn]; vector<int> v[maxn]; int init[maxn]; int A[maxn], B[maxn]; int pre[maxn], maxpre[maxn]; int DL; int zap[maxn], q; struct S { int zero, one; }; using F = bool; S op(S l, S r) { return S{max(l.zero, r.zero), max(l.one, r.one)}; } S e() { return S{0, 0}; } S mapping(F l, S r) { if (!l) return r; return S{r.one, r.zero}; } F composition(F l, F r) { return (l ^ r); } F id() { return false; } void initdfs(int x) { odw[x] = 1; for (auto u : v[x]) { if (!odw[u]) { d[u] = d[x] + 1; initdfs(u); } } } void dfs(int x) { odw[x] = 1; pre[x] = ++DL; maxpre[x] = pre[x]; for (auto u : v[x]) { if (!odw[u]) { d[u] = d[x] + 1; dfs(u); maxpre[x] = max(maxpre[x], maxpre[u]); } } } void toggle(int edge, lazy_segtree<S, op, e, F, mapping, composition, id> &seg) { int node = B[edge]; int a = pre[node], b = maxpre[node] + 1; seg.apply(a, b, true); } vector<int> solve(int root) { 0 && cerr; DL = -1; for (int i = (1); i <= (n); ++i) odw[i] = 0, d[i] = 0, maxpre[i] = 0, pre[i] = 0; dfs(root); for (int i = (1); i <= (n - 1); ++i) { if (d[A[i]] > d[B[i]]) swap(A[i], B[i]); } vector<int> res(q + 1, 0); vector<S> vec(n); for (int i = (1); i <= (n); ++i) { int kt = pre[i]; vec[kt] = {d[i], 0}; } lazy_segtree<S, op, e, F, mapping, composition, id> seg(vec); for (int i = (1); i <= (n - 1); ++i) { if (init[i]) toggle(i, seg); } for (int i = (1); i <= (q); ++i) { toggle(zap[i], seg); S wyn = seg.all_prod(); res[i] = wyn.zero; } return res; } int main() { { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); }; cin >> n; for (int i = (1); i <= (n - 1); ++i) { cin >> A[i] >> B[i] >> init[i]; v[A[i]].push_back(B[i]); v[B[i]].push_back(A[i]); } cin >> q; for (int i = (1); i <= (q); ++i) cin >> zap[i]; for (int i = (1); i <= (n); ++i) odw[i] = 0, d[i] = 0; initdfs(1); int opt = 1; for (int i = (2); i <= (n); ++i) { if (d[i] > d[opt]) opt = i; } int one_end = opt; for (int i = (1); i <= (n); ++i) odw[i] = 0, d[i] = 0; initdfs(opt); opt = 1; for (int i = (2); i <= (n); ++i) { if (d[i] > d[opt]) opt = i; } int second_end = opt; auto a1 = solve(one_end); auto a2 = solve(second_end); for (int i = (1); i <= (q); ++i) cout << max(a1[i], a2[i]) << "\n"; }
#include <bits/stdc++.h> using namespace std; const int max_n = 1111222, inf = 100111222; const int max_v = 2 * max_n; struct state { int max_suf, max_pref, max_h, res; state() : max_suf(0), max_pref(0), max_h(0), res(0) {} state(int max_suf, int max_pref, int max_h, int res) : max_suf(max_suf), max_pref(max_pref), max_h(max_h), res(res) {} }; struct node { state a[2]; int min_h; node() {} node(int h, int col) { min_h = h; a[col] = {-h, -h, h, 0}; a[col ^ 1] = {-inf, -inf, -inf, -inf}; } void flip() { swap(a[0], a[1]); } int get_res() const { return max(a[0].res, a[1].res); } }; state merge(const state &a, const state &b, int amnh, int bmnh) { return { max(b.max_suf, max(a.max_suf, a.max_h - 2 * bmnh)), max(a.max_pref, max(b.max_pref, b.max_h - 2 * amnh)), max(a.max_h, b.max_h), max(a.res, max(b.res, max(a.max_suf + b.max_h, a.max_h + b.max_pref)))}; } node merge(const node &a, const node &b) { node res; res.min_h = min(a.min_h, b.min_h); res.a[0] = merge(a.a[0], b.a[0], a.min_h, b.min_h); res.a[1] = merge(a.a[1], b.a[1], a.min_h, b.min_h); return res; } ostream &operator<<(ostream &os, const state &s) { os << s.max_suf << " " << s.max_pref << " " << s.max_h << " " << s.res; return os; } ostream &operator<<(ostream &os, const node &nd) { os << nd.min_h << "col0 = " << nd.a[0] << " " << "col1 = " << nd.a[1]; return os; } struct tree { node a[max_v]; bool f[max_v]; void build(int v, int l, int r, const vector<int> &h, const vector<int> &col) { if (l == r) { assert(v < max_v); a[v] = node(h[l], col[l]); f[v] = 0; return; } int mid = (l + r) / 2; build(2 * v, l, mid, h, col); build(2 * v + 1, mid + 1, r, h, col); a[v] = merge(a[2 * v], a[2 * v + 1]); } void push(int v) { if (f[v]) { f[2 * v] ^= 1; f[2 * v + 1] ^= 1; a[2 * v].flip(); a[2 * v + 1].flip(); f[v] = 0; } } void update(int v, int tl, int tr, int l, int r) { if (tl == l && tr == r) { f[v] ^= 1; a[v].flip(); return; } push(v); int mid = (tl + tr) / 2; if (r <= mid) { update(2 * v, tl, mid, l, r); } else if (l > mid) { update(2 * v + 1, mid + 1, tr, l, r); } else { update(2 * v, tl, mid, l, mid); update(2 * v + 1, mid + 1, tr, mid + 1, r); } a[v] = merge(a[2 * v], a[2 * v + 1]); } }; int n, m, col[max_n], h[max_n], l[max_n], r[max_n]; int U[max_n], V[max_n], x[max_n]; vector<int> g[max_n], order_h, order_col; tree t; void dfs(int v, int p) { l[v] = order_h.size(); order_h.push_back(h[v]); order_col.push_back(col[v]); for (int id : g[v]) { const int to = U[id] ^ V[id] ^ v; if (to == p) { continue; } if (to != V[id]) { swap(U[id], V[id]); } col[to] = col[v] ^ x[id]; h[to] = h[v] + 1; dfs(to, v); order_h.push_back(h[v]); order_col.push_back(col[v]); } r[v] = order_h.size() - 1; } int main() { scanf("%d", &n); for (int i = 1; i < n; ++i) { scanf("%d%d%d", &U[i], &V[i], &x[i]); --U[i]; --V[i]; g[U[i]].push_back(i); g[V[i]].push_back(i); } dfs(0, -1); t.build(1, 0, order_h.size() - 1, order_h, order_col); scanf("%d", &m); while (m--) { int id; scanf("%d", &id); t.update(1, 0, order_h.size() - 1, l[V[id]], r[V[id]]); int ans = t.a[1].get_res(); ans = max(ans, 0); printf("%d\n", ans); } return 0; }
#include <bits/stdc++.h> using namespace std; int n, q; vector<vector<pair<int, int> > > graph; vector<pair<int, int> > edges; class SegmentTree { struct node_t { int best[2]; int lazy; node_t() { best[0] = 0; best[1] = 0; lazy = 0; } node_t operator+(const node_t &other) const { node_t ans; for (int i = 0; i < 2; i++) { ans.best[i] = max(this->best[i], other.best[i]); } ans.lazy = 0; return ans; } void propag(int lazy) { if (lazy) { swap(best[0], best[1]); this->lazy ^= lazy; } } }; int n; vector<node_t> aint; void propag(int nod, int st, int dr) { if (st == dr || aint[nod].lazy == 0) { return; } aint[nod * 2].propag(aint[nod].lazy); aint[nod * 2 + 1].propag(aint[nod].lazy); aint[nod].lazy = 0; } void build(int nod, int st, int dr, const vector<int> &lvl, const vector<int> &tp) { if (st == dr) { aint[nod].best[tp[st]] = lvl[st]; aint[nod].best[tp[st] ^ 1] = 0; return; } int mid = (st + dr) / 2; build(nod * 2, st, mid, lvl, tp); build(nod * 2 + 1, mid + 1, dr, lvl, tp); aint[nod] = aint[nod * 2] + aint[nod * 2 + 1]; } void flip(int nod, int st, int dr, int l, int r) { propag(nod, st, dr); if (dr < l || st > r) { return; } if (l <= st && dr <= r) { aint[nod].propag(1); return; } int mid = (st + dr) / 2; flip(nod * 2, st, mid, l, r); flip(nod * 2 + 1, mid + 1, dr, l, r); aint[nod] = aint[nod * 2] + aint[nod * 2 + 1]; } public: SegmentTree(int n, const vector<int> &lvl, const vector<int> &tp) { this->n = n; aint = vector<node_t>(4 * n + 5, node_t()); build(1, 1, n, lvl, tp); } SegmentTree() { ; } void flip(int l, int r) { flip(1, 1, n, l, r); } int query() { return aint[1].best[0]; } }; class TreeWrapper { SegmentTree aint; vector<int> lvl; vector<int> tp; vector<int> l; vector<int> r; int lst = 0; void dfs(int nod, pair<int, int> tata, const vector<vector<pair<int, int> > > &graph) { l[nod] = ++lst; lvl[l[nod]] = 1 + lvl[l[tata.first]]; tp[l[nod]] = tp[l[tata.first]] ^ tata.second; for (auto it : graph[nod]) { if (it.first == tata.first) { continue; } dfs(it.first, {nod, it.second}, graph); } r[nod] = lst; } public: TreeWrapper(int root, const vector<vector<pair<int, int> > > &graph) { lst = 0; l = vector<int>(graph.size(), 0); r = vector<int>(graph.size(), 0); lvl = vector<int>(graph.size(), 0); tp = vector<int>(graph.size(), 0); dfs(root, {0, 0}, graph); aint = SegmentTree((int)graph.size() - 1, lvl, tp); } void flip(pair<int, int> a) { if (lvl[l[a.first]] > lvl[l[a.second]]) { swap(a.first, a.second); } aint.flip(l[a.second], r[a.second]); } int query() { return aint.query(); } }; pair<int, int> dfs(int nod, int tata) { pair<int, int> ans = {0, nod}; for (auto it : graph[nod]) { if (it.first == tata) { continue; } pair<int, int> tmp = dfs(it.first, nod); tmp.first++; ans = max(ans, tmp); } return ans; } int main() { scanf("%d", &n); graph = vector<vector<pair<int, int> > >(n + 1, vector<pair<int, int> >()); edges = vector<pair<int, int> >(n, {0, 0}); for (int i = 1; i < n; i++) { int x, y, t; scanf("%d %d %d", &x, &y, &t); graph[x].push_back({y, t}); graph[y].push_back({x, t}); edges[i] = {x, y}; } int a = dfs(1, 0).second; int b = dfs(a, 0).second; TreeWrapper fst(a, graph), snd(b, graph); scanf("%d", &q); while (q--) { int id; scanf("%d", &id); fst.flip(edges[id]); snd.flip(edges[id]); printf("%d\n", max(fst.query(), snd.query()) - 1); } return 0; }
#include <bits/stdc++.h> using namespace std; const int next_x[8] = {0, 1, -1, 0, 1, 1, -1, -1}; const int next_y[8] = {1, 0, 0, -1, 1, -1, -1, 1}; const int inf = 1e9 + 5; const long long linf = 1e18 + 5; const double PI = acos(-1.0); const int MAXN = 1e6 + 5; const int N = 4e6 + 5; const long double eps = 1e-8; const long double fix = 1e-2; namespace io { const int SIZE = (1 << 21) + 1; char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c, qu[55]; int f, qr; inline void flush() { fwrite(obuf, 1, oS - obuf, stdout); oS = obuf; } inline void putc(char x) { *oS++ = x; if (oS == oT) flush(); } template <typename A> inline bool read(A &x) { for (f = 1, c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++); c < '0' || c > '9'; c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) if (c == '-') f = -1; else if (c == EOF) return 0; for (x = 0; c <= '9' && c >= '0'; c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) x = x * 10 + (c & 15); x *= f; return 1; } inline bool read(char &x) { while ((x = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) == ' ' || x == '\n' || x == '\r') ; return x != EOF; } inline bool read(char *x) { while ((*x = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) == '\n' || *x == ' ' || *x == '\r') ; if (*x == EOF) return 0; while (!(*x == '\n' || *x == ' ' || *x == '\r' || *x == EOF)) *(++x) = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++); *x = 0; return 1; } template <typename A, typename... B> inline bool read(A &x, B &...y) { return read(x) && read(y...); } template <typename A> inline bool write(A x) { if (!x) putc('0'); if (x < 0) putc('-'), x = -x; while (x) qu[++qr] = x % 10 + '0', x /= 10; while (qr) putc(qu[qr--]); return 0; } inline bool write(char x) { putc(x); return 0; } inline bool write(const char *x) { while (*x) { putc(*x); ++x; } return 0; } inline bool write(char *x) { while (*x) { putc(*x); ++x; } return 0; } template <typename A, typename... B> inline bool write(A x, B... y) { return write(x) || write(y...); } struct Flusher_ { ~Flusher_() { flush(); } } io_flusher_; } // namespace io namespace seg { int mx[MAXN * 4][2], rev[MAXN * 4]; void dorev(int cnt) { rev[cnt] ^= 1, swap(mx[cnt][0], mx[cnt][1]); } void up(int cnt) { for (int k = (0), I = (1) + 1; k < I; ++k) mx[cnt][k] = max(mx[(cnt << 1)][k], mx[(cnt << 1 | 1)][k]); } void down(int cnt) { if (rev[cnt]) dorev((cnt << 1)), dorev((cnt << 1 | 1)), rev[cnt] = 0; } void build(int l, int r, int a[], int d[], int cnt) { rev[cnt] = 0; if (l == r) { mx[cnt][a[l]] = d[l], mx[cnt][!a[l]] = 0; return; } build(l, ((l + r) / 2), a, d, (cnt << 1)), build(((l + r) / 2) + 1, r, a, d, (cnt << 1 | 1)), up(cnt); } void flip(int l, int r, int nl, int nr, int cnt) { if (l == nl && r == nr) return dorev(cnt); down(cnt); if (nr <= ((l + r) / 2)) flip(l, ((l + r) / 2), nl, nr, (cnt << 1)); else if (nl > ((l + r) / 2)) flip(((l + r) / 2) + 1, r, nl, nr, (cnt << 1 | 1)); else flip(l, ((l + r) / 2), nl, ((l + r) / 2), (cnt << 1)), flip(((l + r) / 2) + 1, r, ((l + r) / 2) + 1, nr, (cnt << 1 | 1)); up(cnt); } } // namespace seg int n, m, tim = 0; int u[MAXN], v[MAXN], w[MAXN], q[MAXN]; int a[MAXN], d[MAXN], _a[MAXN], _d[MAXN], ans[MAXN], st[MAXN], ed[MAXN], node[MAXN]; struct edge { int u, v, w, next; } e[MAXN * 2]; int pre[MAXN], edge_cnt = 0; void addedge(int u, int v, int w = 0) { edge_cnt = edge_cnt + 1, e[edge_cnt].u = u, e[edge_cnt].v = v, e[edge_cnt].w = w, e[edge_cnt].next = pre[u], pre[u] = edge_cnt; }; void dfs(int u, int fa) { st[u] = ++tim, node[tim] = u, d[u] = d[fa] + 1; for (long long i = pre[u], v = e[i].v, w = e[i].w; i; i = e[i].next, v = e[i].v, w = e[i].w) if (v != fa) a[v] = a[u] ^ w, dfs(v, u); ed[u] = tim; } void solve(int root) { tim = 0, a[root] = 0, d[0] = -1, dfs(root, 0); for (int i = (1), I = (n) + 1; i < I; ++i) _a[i] = a[node[i]], _d[i] = d[node[i]]; seg::build(1, n, _a, _d, 1); for (int i = (1), I = (m) + 1; i < I; ++i) { int x = d[u[q[i]]] > d[v[q[i]]] ? u[q[i]] : v[q[i]]; seg::flip(1, n, st[x], ed[x], 1), ans[i] = max(ans[i], seg::mx[1][0]); } } int find(int u, int fa) { int ans = u; d[u] = d[fa] + 1; for (int i = pre[u], v = e[i].v; i; i = e[i].next, v = e[i].v) if (v != fa) { int res = find(v, u); if (d[res] > d[ans]) ans = res; } return ans; } int work() { scanf("%d", &n); for (int i = (1), I = (n - 1) + 1; i < I; ++i) { scanf("%d%d%d", &u[i], &v[i], &w[i]); addedge(u[i], v[i], w[i]), addedge(v[i], u[i], w[i]); } scanf("%d", &m); for (int i = (1), I = (m) + 1; i < I; ++i) scanf("%d", &q[i]); int root; solve(root = find(1, 0)), solve(find(root, 0)); for (int i = (1), I = (m) + 1; i < I; ++i) printf("%d\n", ans[i]); return 0; } int main() { work(); return 0; }
#include <bits/stdc++.h> const int MAXN = 6e5; int n, m, root, tim, edge; int U[MAXN | 1], V[MAXN | 1], W[MAXN | 1], dfn[MAXN | 1], size[MAXN | 1], xorv[MAXN | 1], ID[MAXN | 1], depth[MAXN | 1], fst[MAXN | 1], ans[MAXN | 1]; std::vector<int> que; struct Edge { int to, w, nxt; Edge(int _to = 0, int _w = 0, int _nxt = 0) : to(_to), w(_w), nxt(_nxt) {} } e[MAXN << 1]; inline int read() { register int x = 0, v = 1; register char ch = getchar(); while (!isdigit(ch)) { if (ch == '-') v = -1; ch = getchar(); } while (isdigit(ch)) { x = x * 10 + ch - '0'; ch = getchar(); } return x * v; } inline void add_edge(int a, int b, int c) { e[++edge] = Edge(b, c, fst[a]); fst[a] = edge; } int BFS(int x) { int ans = 1; bool vis[MAXN | 1]; std::queue<int> q; memset(vis, 0, sizeof(vis)); q.push(x); vis[x] = 1; do { int from = q.front(); q.pop(); ans = from; for (int k = fst[from]; k; k = e[k].nxt) { int to = e[k].to; if (vis[to]) continue; vis[to] = 1; q.push(to); } } while (!q.empty()); return ans; } void dfs(int x, int fa) { ID[dfn[x] = ++tim] = x; size[x] = 1; depth[x] = depth[fa] + 1; for (int k = fst[x]; k; k = e[k].nxt) { int to = e[k].to, w = e[k].w; if (to == fa) continue; xorv[to] = xorv[x] ^ w; dfs(to, x); size[x] += size[to]; } } namespace SegmentTree { int max0[MAXN << 2 | 1], max1[MAXN << 1 | 1], tag[MAXN << 1 | 1]; void push_up(int o) { max0[o] = std::max(max0[o << 1], max0[o << 1 | 1]); max1[o] = std::max(max1[o << 1], max1[o << 1 | 1]); } void push_down(int o) { if (!tag[o]) return; std::swap(max0[o << 1], max1[o << 1]); std::swap(max0[o << 1 | 1], max1[o << 1 | 1]); tag[o << 1] ^= 1; tag[o << 1 | 1] ^= 1; tag[o] = 0; } void build(int o, int l, int r) { tag[o] = 0; max0[o] = max1[o] = 0; if (l == r) { if (xorv[ID[l]]) max1[o] = depth[ID[l]]; else max0[o] = depth[ID[l]]; return; } int mid = (l + r) >> 1; build(o << 1, l, mid); build(o << 1 | 1, mid + 1, r); push_up(o); } void flip(int o, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) { std::swap(max0[o], max1[o]); tag[o] ^= 1; return; } int mid = (l + r) >> 1; push_down(o); if (ql <= mid) flip(o << 1, l, mid, ql, qr); if (mid < qr) flip(o << 1 | 1, mid + 1, r, ql, qr); push_up(o); } int query(int o, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) return max1[o]; int mid = (l + r) >> 1, res = 0; push_down(o); if (ql <= mid) res = query(o << 1, l, mid, ql, qr); if (mid < qr) res = std::max(res, query(o << 1 | 1, mid + 1, r, ql, qr)); return res; } } // namespace SegmentTree using namespace SegmentTree; int main() { n = read(); for (int i = 1; i < n; ++i) { U[i] = read(); V[i] = read(); W[i] = read(); add_edge(U[i], V[i], W[i]); add_edge(V[i], U[i], W[i]); } root = BFS(1); int lst = root; dfs(root, 0); build(1, 1, n); m = read(); for (int i = 1; i <= m; ++i) { int x = read(), u = U[x], v = V[x]; que.push_back(x); if (depth[u] < depth[v]) std::swap(u, v); flip(1, 1, n, dfn[u], dfn[u] + size[u] - 1); ans[i] = max0[1] - 1; } root = BFS(root); xorv[root] = 0; tim = 0; dfs(root, 0); build(1, 1, n); for (int i = 1; i <= m; ++i) { int x = que[i - 1], u = U[x], v = V[x]; if (depth[u] < depth[v]) std::swap(u, v); flip(1, 1, n, dfn[u], dfn[u] + size[u] - 1); ans[i] = std::max(max0[1] - 1, ans[i]); } for (int i = 1; i <= m; ++i) printf("%d\n", ans[i]); return 0; }
#include <bits/stdc++.h> template <class T, class U> inline bool smin(T &x, const U &y) { return y < x ? x = y, 1 : 0; } template <class T, class U> inline bool smax(T &x, const U &y) { return x < y ? x = y, 1 : 0; } using LL = long long; using PII = std::pair<int, int>; struct Info { int c, len, d[2][2], r[2]; Info() : c(0), len(0) { d[0][0] = 0, d[0][1] = -1e9; d[1][0] = 0, d[1][1] = -1e9; r[0] = r[1] = -1e9; } void reverse() { std::swap(d[0][0], d[1][0]); std::swap(d[0][1], d[1][1]); } Info &compress(Info a, Info b) { c = a.c ^ b.c; len = a.len + b.len; d[0][0] = std::max(a.d[0][0], a.len + b.d[0][a.c]); d[0][1] = std::max(a.d[0][1], a.len + b.d[0][!a.c]); d[1][0] = std::max(b.d[1][0], b.len + a.d[1][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[1][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[1][0] + b.d[0][0], a.d[1][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[1][0] + b.d[0][1], a.d[1][1] + b.d[0][0]}); return *this; } Info &rakeToPath(Info a, Info b) { c = b.c; len = b.len; d[0][0] = std::max(a.d[0][0], b.d[0][0]); d[0][1] = std::max(a.d[0][1], b.d[0][1]); d[1][0] = std::max(b.d[1][0], b.len + a.d[0][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[0][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[0][0] + b.d[0][0], a.d[0][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[0][0] + b.d[0][1], a.d[0][1] + b.d[0][0]}); return *this; } Info &rake(Info a, Info b) { d[0][0] = std::max(a.d[0][0], b.d[0][0]); d[0][1] = std::max(a.d[0][1], b.d[0][1]); r[0] = std::max( {a.r[0], b.r[0], a.d[0][0] + b.d[0][0], a.d[0][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[0][0] + b.d[0][1], a.d[0][1] + b.d[0][0]}); return *this; } }; struct SplayTree { static SplayTree *null; SplayTree *ch[3], *fa; bool rev; Info info; SplayTree() { static bool _init = true; if (_init) { _init = false; null = new SplayTree; null->ch[0] = null->ch[1] = null->ch[2] = null->fa = null; } ch[0] = ch[1] = ch[2] = fa = null; } bool notRoot() const { return fa->ch[0] == this || fa->ch[1] == this; } void reverse() { rev ^= 1; std::swap(ch[0], ch[1]); info.reverse(); } bool dir() const { return fa->ch[1] == this; } SplayTree *sch(int d, SplayTree *c) { return ch[d] = c, c->fa = this; } void rotate() { SplayTree *p = fa; p->pushdown(), pushdown(); bool d = dir(); fa = p->fa; if (fa != null) { fa->ch[fa->ch[2] == p ? 2 : p->dir()] = this; } p->sch(d, ch[!d])->pushup(); sch(!d, p)->pushup(); } SplayTree *splay(SplayTree *p = null) { for (pushdown(); fa != p && notRoot(); rotate()) { if (fa->fa != p && fa->notRoot()) { fa->fa->pushdown(); (fa->dir() == dir() ? fa : this)->rotate(); } } return this; } SplayTree *splayExt(int d) { SplayTree *o = this; while (o->pushdown(), o->ch[d] != null) o = o->ch[d]; return o->splay(fa); } virtual void pushup() {} virtual void pushdown() {} }; SplayTree *SplayTree::null; struct CompressTree : SplayTree { void pushup() { info.compress(ch[0]->info, Info().rakeToPath(ch[2]->info, ch[1]->info)); } void pushdown() { if (rev) { rev = false; ch[0]->reverse(), ch[1]->reverse(); } } }; struct RakeTree : SplayTree { void pushup() { info.rake(ch[0]->info, Info().rake(ch[2]->info, ch[1]->info)); } }; void splice(SplayTree *o) { o->splay(); o = o->fa->splay(); SplayTree *c = o->ch[2]; c->pushdown(); if (o->ch[1] != SplayTree::null) { std::swap(o->ch[1]->fa, c->ch[2]->fa); std::swap(o->ch[1], c->ch[2]); } else { o->sch(1, c->ch[2]); if (c->ch[0] != SplayTree::null) { c->ch[0]->splayExt(1); c->ch[0]->sch(1, c->ch[1]); o->ch[2] = c->ch[0]; } else { c->ch[1]->pushdown(); o->ch[2] = c->ch[1]; } c = o->ch[2], c->fa = o; } c->pushup(), o->pushup(); o->ch[1]->rotate(); } void access(SplayTree *o) { o->splay(); if (o->ch[1] != SplayTree::null) { SplayTree *c = new RakeTree; c->sch(0, o->ch[2]); c->sch(2, o->ch[1]); c->pushup(); o->ch[1] = SplayTree::null; o->sch(2, c); o->pushup(); } while (o->fa != SplayTree::null) splice(o->fa); } void evert(SplayTree *o) { access(o), o->reverse(), o->pushdown(); } void link(SplayTree *x, SplayTree *y, int c) { access(x); evert(y); y->pushdown(); SplayTree *e = new CompressTree; e->info.len = 1, e->info.c = c; y->sch(0, e)->pushup(); x->sch(1, y)->pushup(); } constexpr int N(3e5 + 5); int main() { std::ios::sync_with_stdio(false); std::cin.tie(nullptr); int n, m; std::cin >> n; SplayTree *t = new CompressTree[n + 1]; assert(SplayTree::null); std::vector<int> u(n - 1), v(n - 1); for (int i = 0, c; i < n - 1; i++) { std::cin >> u[i] >> v[i] >> c; link(t + u[i], t + v[i], c); } std::cin >> m; while (m--) { int i; std::cin >> i; i--; evert(t + u[i]), access(t + v[i]); t[v[i]].pushdown(); t[u[i]].pushdown(); t[u[i]].ch[1]->info.c ^= 1; t[u[i]].pushup(); t[v[i]].pushup(); std::cout << t[v[i]].info.r[0] << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; int n; int u[600001], v[600001], z[600001]; int id1, id2; int dist[600001]; vector<pair<int, int> > nxt[600001]; void DFS(int u, int par, int dd) { dist[u] = dd; for (auto t : nxt[u]) { int tt = t.first; if (tt != par) DFS(tt, u, dd + 1); } } int l[600001 * 2][2], r[600001 * 2][2], ma[600001 * 2][2], mi[600001 * 2][2], fu[600001 * 2][2]; int lu[600001][2], ru[600001][2], a[600001][2]; int ff; int h[2]; void build2(int id, int u, int lb, int rb) { if (lb == rb) { ma[u][id] = mi[u][id] = a[lb][id]; return; } int mid = (lb + rb) / 2; build2(id, l[u][id] = ++h[id], lb, mid); build2(id, r[u][id] = ++h[id], mid + 1, rb); int fl = l[u][id]; int fr = r[u][id]; ma[u][id] = max(ma[fl][id], ma[fr][id]); mi[u][id] = min(mi[fl][id], mi[fr][id]); } void eval(int id, int u) { int lr = l[u][id]; int rr = r[u][id]; int mal = ma[lr][id]; int mil = mi[lr][id]; if (fu[lr][id]) { int t = mal; mal = -mil; mil = -t; } int mar = ma[rr][id]; int mir = mi[rr][id]; if (fu[rr][id]) { int t = mar; mar = -mir; mir = -t; } ma[u][id] = max(mal, mar); mi[u][id] = min(mil, mir); } void push_down(int id, int u) { int lr = l[u][id]; int rr = r[u][id]; fu[lr][id] ^= fu[u][id]; fu[rr][id] ^= fu[u][id]; fu[u][id] = 0; eval(id, u); } void update(int id, int u, int lb, int rb, int lq, int rq) { if (rq < lb || rb < lq) { return; } if (lq <= lb && rb <= rq) { fu[u][id] ^= 1; return; } push_down(id, u); int mid = (lb + rb) / 2; update(id, l[u][id], lb, mid, lq, rq); update(id, r[u][id], mid + 1, rb, lq, rq); eval(id, u); } int query(int id, int u) { return (fu[u][id] ? -mi[u][id] : ma[u][id]); } void DFS3(int id, int u, int par, int depth, int multi) { ff++; lu[u][id] = ff; a[ff][id] = depth * multi; for (auto t : nxt[u]) { int tt = t.first; int nm = multi * (z[t.second] == 1 ? -1 : 1); if (tt != par) DFS3(id, tt, u, depth + 1, nm); } ru[u][id] = ff; } void build(int u, int id) { h[id] = ff = 0; DFS3(id, u, -1, 0, 1); build2(id, h[id], 1, n); } int main() { scanf("%d", &n); for (int i = 1; i <= n - 1; i++) { scanf("%d%d%d", &u[i], &v[i], &z[i]); nxt[u[i]].push_back(make_pair(v[i], i)); nxt[v[i]].push_back(make_pair(u[i], i)); } DFS(1, -1, 0); id1 = 1; for (int i = 2; i <= n; i++) if (dist[i] > dist[id1]) id1 = i; for (int i = 1; i <= n; i++) dist[i] = 0; DFS(id1, -1, 0); id2 = 1; for (int i = 2; i <= n; i++) if (dist[i] > dist[id2]) id2 = i; build(id1, 0); build(id2, 1); int m; scanf("%d", &m); while (m--) { int id; scanf("%d", &id); int uu = u[id]; int vv = v[id]; int ret = 0; for (int j = 0; j <= 1; j++) { int x = (lu[uu][j] < lu[vv][j] ? vv : uu); int ll = lu[x][j]; int rr = ru[x][j]; update(j, 0, 1, n, ll, rr); ret = max(ret, query(j, 0)); } printf("%d\n", ret); } }
#include <bits/stdc++.h> namespace atcoder { namespace internal { int ceil_pow2(int n) { int x = 0; while ((1U << x) < (unsigned int)(n)) x++; return x; } int bsf(unsigned int n) { return __builtin_ctz(n); } } // namespace internal } // namespace atcoder namespace atcoder { template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()> struct lazy_segtree { public: lazy_segtree() : lazy_segtree(0) {} lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {} lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) { log = internal::ceil_pow2(_n); size = 1 << log; d = std::vector<S>(2 * size, e()); lz = std::vector<F>(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) { update(i); } } void set(int p, S x) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = x; for (int i = 1; i <= log; i++) update(p >> i); } S get(int p) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); return d[p]; } S prod(int l, int r) { assert(0 <= l && l <= r && r <= _n); if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push(r >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S all_prod() { return d[1]; } void apply(int p, F f) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = mapping(f, d[p]); for (int i = 1; i <= log; i++) update(p >> i); } void apply(int l, int r, F f) { assert(0 <= l && l <= r && r <= _n); if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } template <bool (*g)(S)> int max_right(int l) { return max_right(l, [](S x) { return g(x); }); } template <class G> int max_right(int l, G g) { assert(0 <= l && l <= _n); assert(g(e())); if (l == _n) return _n; l += size; for (int i = log; i >= 1; i--) push(l >> i); S sm = e(); do { while (l % 2 == 0) l >>= 1; if (!g(op(sm, d[l]))) { while (l < size) { push(l); l = (2 * l); if (g(op(sm, d[l]))) { sm = op(sm, d[l]); l++; } } return l - size; } sm = op(sm, d[l]); l++; } while ((l & -l) != l); return _n; } template <bool (*g)(S)> int min_left(int r) { return min_left(r, [](S x) { return g(x); }); } template <class G> int min_left(int r, G g) { assert(0 <= r && r <= _n); assert(g(e())); if (r == 0) return 0; r += size; for (int i = log; i >= 1; i--) push((r - 1) >> i); S sm = e(); do { r--; while (r > 1 && (r % 2)) r >>= 1; if (!g(op(d[r], sm))) { while (r < size) { push(r); r = (2 * r + 1); if (g(op(d[r], sm))) { sm = op(d[r], sm); r--; } } return r + 1 - size; } sm = op(d[r], sm); } while ((r & -r) != r); return 0; } private: int _n, size, log; std::vector<S> d; std::vector<F> lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; } // namespace atcoder using namespace std; using namespace atcoder; using ll = long long; using P = pair<int, int>; using VI = vector<int>; using VVI = vector<VI>; struct HLD { std::vector<std::vector<int>>& to; int root, n; std::vector<int> sz, parent, depth, idx, ridx, head; HLD(std::vector<std::vector<int>>& to, int root = 0) : to(to), root(root), n(to.size()), sz(n), parent(n), depth(n), idx(n), ridx(n), head(n) { init_tree_data(root); int x = 0; assign_idx(root, root, x); } void init_tree_data(int u, int p = -1, int d = 0) { parent[u] = p; depth[u] = d; int s = 1; for (int v : to[u]) { if (v == p) continue; init_tree_data(v, u, d + 1); s += sz[v]; } sz[u] = s; } void assign_idx(int u, int h, int& nxt, int p = -1) { head[u] = h; idx[u] = nxt++; if (sz[u] == 1) { ridx[u] = nxt; return; } int mxsize = 0; int mi; for (int v : to[u]) { if (v == p) continue; if (sz[v] > mxsize) { mxsize = sz[v]; mi = v; } } assign_idx(mi, h, nxt, u); for (int v : to[u]) { if (v == p || v == mi) continue; assign_idx(v, v, nxt, u); } ridx[u] = nxt; } }; struct S { int even, odd; }; S op(S x, S y) { return {max(x.even, y.even), max(x.odd, y.odd)}; } S e() { return {-1, -1}; } S mapping(bool f, S x) { if (f) return {x.odd, x.even}; else return x; } bool composition(bool f, bool g) { return f ^ g; } bool id() { return false; } struct E { int u, v, state; }; VVI to; P dfs(int u, int p = -1, int depth = 0) { P ret = {u, depth}; for (int v : to[u]) { if (v == p) continue; P r = dfs(v, u, depth + 1); if (r.second > ret.second) ret = r; } return ret; } int main() { cin.tie(0); int n; cin >> n; to.resize(n); vector<E> es(n - 1); for (int i = 0; i < (n - 1); ++i) { int u, v, t; cin >> u >> v >> t; --u, --v; es[i] = {u, v, t}; to[u].push_back(v); to[v].push_back(u); } int m; cin >> m; VI query(m); for (int i = 0; i < (m); ++i) { cin >> query[i]; query[i]--; } VI ab(2); ab[0] = dfs(0).first; ab[1] = dfs(ab[0]).first; VVI ans(2, VI(m)); for (int tt = 0; tt < (2); ++tt) { int a = ab[tt]; HLD hld(to, a); VI is_odd(n); for (int i = 0; i < (n - 1); ++i) { int u = es[i].u, v = es[i].v, s = es[i].state; if (hld.parent[u] == v) { swap(u, v); swap(es[i].u, es[i].v); } is_odd[v] = s; } queue<int> que; que.push(a); while (!que.empty()) { int u = que.front(); que.pop(); for (int v : to[u]) { if (v == hld.parent[u]) continue; is_odd[v] ^= is_odd[u]; que.push(v); } } vector<S> init_vec(n); for (int i = 0; i < (n); ++i) { if (is_odd[i]) { init_vec[hld.idx[i]] = {-1, hld.depth[i]}; } else { init_vec[hld.idx[i]] = {hld.depth[i], -1}; } } lazy_segtree<S, op, e, bool, mapping, composition, id> seg(init_vec); for (int i = 0; i < (m); ++i) { int ei = query[i]; int v = es[ei].v; int vin = hld.idx[v], vout = hld.ridx[v]; seg.apply(vin, vout, true); ans[tt][i] = seg.all_prod().even; } } for (int i = 0; i < (m); ++i) cout << max(ans[0][i], ans[1][i]) << '\n'; }
#include <bits/stdc++.h> template <class T, class U> inline bool smin(T &x, const U &y) { return y < x ? x = y, 1 : 0; } template <class T, class U> inline bool smax(T &x, const U &y) { return x < y ? x = y, 1 : 0; } using LL = long long; using PII = std::pair<int, int>; constexpr int N(5e5 + 5); struct Info { int c, len, d[2][2], r[2]; Info() : c(0), len(0) { d[0][0] = 0, d[0][1] = -1e9; d[1][0] = 0, d[1][1] = -1e9; r[0] = r[1] = -1e9; } void reverse() { std::swap(d[0][0], d[1][0]); std::swap(d[0][1], d[1][1]); } Info &compress(Info a, Info b) { c = a.c ^ b.c; len = a.len + b.len; d[0][0] = std::max(a.d[0][0], a.len + b.d[0][a.c]); d[0][1] = std::max(a.d[0][1], a.len + b.d[0][!a.c]); d[1][0] = std::max(b.d[1][0], b.len + a.d[1][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[1][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[1][0] + b.d[0][0], a.d[1][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[1][0] + b.d[0][1], a.d[1][1] + b.d[0][0]}); return *this; } Info &rake(Info a, Info b) { c = b.c; len = b.len; d[0][0] = std::max(a.d[0][0], b.d[0][0]); d[0][1] = std::max(a.d[0][1], b.d[0][1]); d[1][0] = std::max(b.d[1][0], b.len + a.d[0][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[0][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[0][0] + b.d[0][0], a.d[0][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[0][0] + b.d[0][1], a.d[0][1] + b.d[0][0]}); return *this; } }; struct SplayTree { static SplayTree *null; SplayTree *ch[3], *fa; bool rev; Info info; SplayTree() : rev(false), info() { static bool init = true; if (init) { init = false; null = new SplayTree; null->ch[0] = null->ch[1] = null->ch[2] = null->fa = null; } ch[0] = ch[1] = ch[2] = fa = null; } bool notRoot() const { return fa->ch[0] == this || fa->ch[1] == this; } void reverse() { rev ^= 1; std::swap(ch[0], ch[1]); info.reverse(); } bool dir() const { return fa->ch[1] == this; } void sch(int d, SplayTree *c) { ch[d] = c, c->fa = this; } void rotate() { SplayTree *p = fa; bool d = dir(); fa = p->fa; if (fa != null) { fa->ch[fa->ch[2] == p ? 2 : p->dir()] = this; } p->sch(d, ch[!d]), sch(!d, p); p->pushup(); } void splay() { static SplayTree *s[N], **t; t = s; for (auto x = this; x->notRoot(); x = x->fa) *++t = x->fa; while (t != s) (*t--)->pushdown(); for (pushdown(); notRoot(); rotate()) { if (fa->notRoot()) { (fa->dir() == dir() ? fa : this)->rotate(); } } pushup(); } virtual void pushup() {} virtual void pushdown() {} virtual ~SplayTree() {} }; SplayTree *SplayTree::null; struct RakeTree : SplayTree { void pushup() { info.rake(ch[0]->info, Info().rake(ch[2]->info, ch[1]->info)); } }; struct CompressTree : SplayTree { void pushup() { info.compress(ch[0]->info, Info().rake(ch[2]->info, ch[1]->info)); } void pushdown() { if (rev) { rev = false; ch[0]->reverse(), ch[1]->reverse(); } } void access() { splay(); if (ch[1] != null) { auto r = new RakeTree; r->sch(0, ch[2]), r->sch(2, ch[1]), r->pushup(); ch[1] = null, sch(2, r), pushup(); } for (; fa != null; rotate()) { fa->splay(); SplayTree *m = fa, *p = m->fa; assert(p != null); p->splay(); if (p->ch[1] != null) { m->sch(2, p->ch[1]); m->pushup(); } else { if (m->ch[0] == null) { p->sch(2, m->ch[1]); } else if (m->ch[1] == null) { p->sch(2, m->ch[0]); } else { auto x = m->ch[0]; x->fa = null; while (x->pushdown(), x->ch[1] != null) x = x->ch[1]; x->splay(); p->sch(2, x); x->sch(1, m->ch[1]); x->pushup(); } delete m; } p->sch(1, this); p->pushup(); } pushup(); } void evert() { access(), reverse(), pushdown(); } }; void link(CompressTree *x, CompressTree *y, int c) { x->access(), y->evert(); auto e = new SplayTree; e->info.len = 1, e->info.c = c; x->sch(1, y), y->sch(0, e); y->pushup(), x->pushup(); } int main() { std::ios::sync_with_stdio(false); std::cin.tie(nullptr); int n, m; std::cin >> n; CompressTree *t = new CompressTree[n + 1]; assert(SplayTree::null); std::vector<int> u(n - 1), v(n - 1); for (int i = 0, c; i < n - 1; i++) { std::cin >> u[i] >> v[i] >> c; link(t + u[i], t + v[i], c); } std::cin >> m; while (m--) { int i; std::cin >> i; i--; t[u[i]].evert(), t[v[i]].access(); t[u[i]].ch[1]->info.c ^= 1; t[u[i]].pushup(); t[v[i]].pushup(); std::cout << t[v[i]].info.r[0] << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> void read(T &x) { int f = 0; x = 0; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) f |= (ch == '-'); for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0'; if (f) x = -x; } const int N = (1 << 20) + 5; int cur[N], in[N], out[N], rev[N], owo[N], col[N], n, Q, x, y; vector<pair<int, int> > e[N]; namespace tree { int d[N], in[N], out[N]; int mn[N][21], lg[N], clk, clk2; int Min(int x, int y) { return d[x] < d[y] ? x : y; } void dfs1(int u, int fa) { d[u] = d[fa] + 1; mn[in[u] = ++clk][0] = u; ::rev[::in[u] = ++clk2] = u; for (auto v : e[u]) { if (v.first == fa) continue; cur[v.second] = v.first; col[v.first] = col[u] ^ owo[v.second]; dfs1(v.first, u); mn[++clk][0] = u; } out[u] = clk; ::out[u] = clk2; } void init() { dfs1(1, 0); lg[0] = -1; for (int i = (1); i <= (clk); i++) { lg[i] = lg[i >> 1] + 1; } for (int i = (clk); i >= (1); i--) { for (int j = 1; i + (1 << j) - 1 <= clk; j++) { mn[i][j] = Min(mn[i][j - 1], mn[i + (1 << (j - 1))][j - 1]); } } } int lca(int x, int y) { x = in[x], y = in[y]; if (x > y) swap(x, y); int t = lg[y - x + 1]; return Min(mn[x][t], mn[y - (1 << t) + 1][t]); } int dist(int x, int y) { if (!x || !y) return -1; return d[x] + d[y] - 2 * d[lca(x, y)]; } void upd(pair<int, int> &res, int x) { int mx = dist(res.first, res.second); int t1 = dist(res.first, x); int t2 = dist(res.second, x); if (t1 >= mx && t1 >= t2) res.second = x; else if (t2 >= mx) res.first = x; } pair<int, int> merge(pair<int, int> a, pair<int, int> b) { pair<int, int> res = a; if (!res.first) res = b; if (b.first) upd(res, b.first); if (b.second) upd(res, b.second); return res; } } // namespace tree namespace seg { pair<pair<int, int>, pair<int, int> > T[N << 2]; int tag[N << 2]; void up(int o) { T[o].first = tree::merge(T[(o << 1)].first, T[(o << 1 | 1)].first); T[o].second = tree::merge(T[(o << 1)].second, T[(o << 1 | 1)].second); } void app(int o) { swap(T[o].first, T[o].second); tag[o] ^= 1; } void down(int o) { if (tag[o]) { app((o << 1)), app((o << 1 | 1)); tag[o] = 0; } } void upd(int o, int l, int r, int x, int y) { if (l == x && y == r) { app(o); return; } down(o); if (x <= ((l + r) >> 1)) upd((o << 1), l, ((l + r) >> 1), x, min(y, ((l + r) >> 1))); if (((l + r) >> 1) < y) upd((o << 1 | 1), ((l + r) >> 1) + 1, r, max(((l + r) >> 1) + 1, x), y); up(o); } void build(int o, int l, int r) { if (l == r) { if (!col[rev[l]]) { T[o].first = make_pair(rev[l], rev[l]); T[o].second = make_pair(0, 0); } else { T[o].second = make_pair(rev[l], rev[l]); T[o].first = make_pair(0, 0); } return; } build((o << 1), l, ((l + r) >> 1)); build((o << 1 | 1), ((l + r) >> 1) + 1, r); up(o); } } // namespace seg int main() { read(n); for (int i = (1); i <= (n - 1); i++) { read(x), read(y), read(owo[i]); e[x].push_back(make_pair(y, i)); e[y].push_back(make_pair(x, i)); } tree::init(); seg::build(1, 1, n); read(Q); while (Q--) { read(x); seg::upd(1, 1, n, in[cur[x]], out[cur[x]]); pair<pair<int, int>, pair<int, int> > ret = seg::T[1]; int ans1 = tree::dist(ret.first.first, ret.first.second); int ans2 = tree::dist(ret.second.first, ret.second.second); printf("%d\n", max(ans1, ans2)); } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = (int)5e5 + 100; struct Node { int dist[2]; int flip; }; struct segment_tree { Node T[N * 4 + 512]; long long val[N]; int bit[N]; void build(int node, int cl, int cr) { if (cl == cr) { T[node].flip = 0; T[node].dist[bit[cl]] = val[cl]; return; } int mid = (cl + cr) / 2; build(node * 2, cl, mid); build(node * 2 + 1, mid + 1, cr); for (int q = 0; q < 2; q++) { T[node].dist[q] = max(T[node * 2].dist[q], T[node * 2 + 1].dist[q]); } } void push(int node, int cl, int cr) { if (T[node].flip) { swap(T[node].dist[0], T[node].dist[1]); if (cl != cr) { T[node * 2].flip ^= 1; T[node * 2 + 1].flip ^= 1; } T[node].flip = 0; } } void update(int node, int cl, int cr, int tl, int tr) { push(node, cl, cr); if (cr < tl || cl > tr) return; if (cl >= tl && cr <= tr) { T[node].flip = 1; push(node, cl, cr); return; } int mid = (cl + cr) / 2; update(node * 2, cl, mid, tl, tr); update(node * 2 + 1, mid + 1, cr, tl, tr); T[node].dist[0] = max(T[node * 2].dist[0], T[node * 2 + 1].dist[0]); T[node].dist[1] = max(T[node * 2].dist[1], T[node * 2 + 1].dist[1]); } }; vector<pair<int, int> > E[N]; int dis[N]; int pap[N]; int tin[N]; int tout[N]; int cc; int ta[N]; int tb[N]; int uu[N]; int vv[N]; int dfs(int node, int pp) { int best = node; int nex; cc++; tin[node] = cc; for (auto x : E[node]) { if (x.first == pp) continue; dis[x.first] = dis[node] + 1; pap[x.first] = (pap[node] ^ x.second); nex = dfs(x.first, node); if (dis[nex] > dis[best]) { best = nex; } } tout[node] = cc; return best; } segment_tree n1, n2; int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); ; int n; cin >> n; int u, v, d; for (int i = 1; i < n; i++) { cin >> u >> v >> d; uu[i] = u; vv[i] = v; E[u].push_back(make_pair(v, d)); E[v].push_back(make_pair(u, d)); } int A = dfs(1, -1); dis[A] = 0; pap[A] = 0; cc = 0; int B = dfs(A, -1); for (int i = 1; i <= n; i++) { n1.val[tin[i]] = dis[i]; n1.bit[tin[i]] = pap[i]; ta[i] = tin[i]; tb[i] = tout[i]; } n1.build(1, 1, n); dis[B] = 0; pap[B] = 0; cc = 0; dfs(B, -1); for (int i = 1; i <= n; i++) { n2.val[tin[i]] = dis[i]; n2.bit[tin[i]] = pap[i]; } n2.build(1, 1, n); int q; cin >> q; int iq; int goal; for (int it = 1; it <= q; it++) { cin >> iq; if (ta[vv[iq]] < ta[uu[iq]]) { goal = uu[iq]; } else { goal = vv[iq]; } n1.update(1, 1, n, ta[goal], tb[goal]); if (tin[vv[iq]] < tin[uu[iq]]) { goal = uu[iq]; } else { goal = vv[iq]; } n2.update(1, 1, n, tin[goal], tout[goal]); cout << max(n1.T[1].dist[0], n2.T[1].dist[0]) << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 1; const int ts = 1 << 21; int n; int eu[N], ev[N], ew[N]; vector<int> adj[N]; int e[N], d2[N]; ; int st[N], en[N]; int ptr = 0; int seq[N]; void dfs(int id, int p) { st[id] = ++ptr; seq[ptr] = id; for (auto c : adj[id]) { if (c == p) continue; e[c] = e[id] + 1; dfs(c, id); seq[++ptr] = id; } en[id] = ptr; } array<int, 9> a[ts]; bool lz[ts]; void putlz(int id) { swap(a[id][1], a[id][2]); swap(a[id][3], a[id][4]); swap(a[id][5], a[id][6]); swap(a[id][7], a[id][8]); } void pull(int id) { int lc = id * 2, rc = id * 2 + 1; for (int i = 0; i <= 8; i++) { a[id][i] = max(a[lc][i], a[rc][i]); } a[id][3] = max(a[id][3], a[lc][1] + a[rc][0]); a[id][4] = max(a[id][4], a[lc][2] + a[rc][0]); a[id][5] = max(a[id][5], a[lc][0] + a[rc][1]); a[id][6] = max(a[id][6], a[lc][0] + a[rc][2]); a[id][7] = max(a[id][7], a[lc][1] + a[rc][5]); a[id][7] = max(a[id][7], a[lc][3] + a[rc][1]); a[id][8] = max(a[id][8], a[lc][2] + a[rc][6]); a[id][8] = max(a[id][8], a[lc][4] + a[rc][2]); } void push(int id) { if (!lz[id]) return; putlz(id * 2); putlz(id * 2 + 1); lz[id * 2] ^= 1; lz[id * 2 + 1] ^= 1; lz[id] = false; } void build(int id, int l, int r) { for (int i = 0; i <= 8; i++) a[id][i] = -1e6; if (l == r) { int d = e[seq[l]]; a[id][0] = -2 * d; a[id][1] = d; a[id][3] = -d; a[id][5] = -d; a[id][7] = 0; return; } int mid = (l + r) / 2; build(id * 2, l, mid); build(id * 2 + 1, mid + 1, r); pull(id); } void upd(int id, int l, int r, int ql, int qr) { if (l > qr || r < ql) return; if (ql <= l && r <= qr) { putlz(id); lz[id] ^= 1; return; } push(id); int mid = (l + r) / 2; upd(id * 2, l, mid, ql, qr); upd(id * 2 + 1, mid + 1, r, ql, qr); pull(id); } int main() { ios::sync_with_stdio(false); cin.tie(0); cin >> n; for (int i = 1; i < n; i++) { cin >> eu[i] >> ev[i] >> ew[i]; int u = eu[i], v = ev[i]; adj[u].push_back(v); adj[v].push_back(u); } dfs(1, 0); build(1, 1, 2 * n - 1); for (int i = 1; i < n; i++) { if (st[eu[i]] > st[ev[i]]) swap(eu[i], ev[i]); if (ew[i]) upd(1, 1, 2 * n - 1, st[ev[i]], en[ev[i]]); } int q; cin >> q; for (int i = 1; i <= q; i++) { int x; cin >> x; upd(1, 1, 2 * n - 1, st[ev[x]], en[ev[x]]); ew[x] ^= 1; cout << max(a[1][7], a[1][8]) << '\n'; } }
#include <bits/stdc++.h> using namespace std; const long long MOD = 1e9 + 7; template <class T> void chmin(T &a, const T &b) { if (a > b) a = b; } template <class T> void chmax(T &a, const T &b) { if (a < b) a = b; } struct Edge { int to, id; long long dist; Edge(int to, long long dist = 1, int id = 0) : to(to), dist(dist), id(id) {} }; struct HeavyLightDecomposition { vector<vector<Edge>> g; vector<int> in, out, head, par, dep, sz; int times; int root; HeavyLightDecomposition(int V, vector<vector<Edge>> &G, int root = 0) : g(G), in(V), out(V), head(V), par(V), dep(V), sz(V), root(root) { times = 0; sz_dfs(root, -1); hld_dfs(root, -1); } void sz_dfs(int now, int p) { par[now] = p; sz[now] = 1; if (p == -1) dep[now] = 0; else dep[now] = dep[p] + 1; for (auto &e : g[now]) { if (e.to == p) continue; sz_dfs(e.to, now); sz[now] += sz[e.to]; if (sz[e.to] > sz[g[now][0].to]) swap(e, g[now][0]); } } void hld_dfs(int now, int p) { in[now] = times++; for (auto e : g[now]) { if (e.to == p) continue; head[e.to] = (e.to == g[now][0].to ? head[now] : e.to); hld_dfs(e.to, now); } out[now] = times; } int lca(int u, int v) { for (;; v = par[head[v]]) { if (in[u] > in[v]) swap(u, v); if (head[u] == head[v]) return u; } } int distance(int u, int v) { return dep[u] + dep[v] - 2 * dep[lca(u, v)]; } template <class T, class G> void update(int v, const T &x, const G &g) { g(in[v], out[v], x); } template <class F> void query(int u, int v, const F &f, bool isedge) { for (;; v = par[head[v]]) { if (in[u] > in[v]) swap(u, v); if (head[u] == head[v]) break; f(in[head[v]], in[v] + 1); } if (isedge && u == v) return; f(in[u] + isedge, in[v] + 1); } }; template <typename T, typename S> struct LazySegmentTree { int n; vector<T> data; vector<S> lazy; T te; S se; inline void merge_functions(S &lazy, S &val) { lazy ^= val; } inline void operate(T &data, S &val, int len) { swap(data.first, data.second); } inline T merge_values(T &x, T &y) { return make_pair(max(x.first, y.first), max(x.second, y.second)); } LazySegmentTree() {} LazySegmentTree(int sz, T te, S se) : te(te), se(se) { n = 1; while (n < sz) n *= 2; data.resize(2 * n - 1, te); lazy.resize(2 * n - 1, se); } void build(const vector<T> &A) { for (int k = 0; k < int(A.size()); k++) data[k + n - 1] = A[k]; for (int k = n - 2; k >= 0; k--) data[k] = merge_values(data[2 * k + 1], data[2 * k + 2]); } void eval(int k, int l, int r) { if (lazy[k] == se) return; operate(data[k], lazy[k], r - l); if (r - l > 1) { merge_functions(lazy[2 * k + 1], lazy[k]); merge_functions(lazy[2 * k + 2], lazy[k]); } lazy[k] = se; } void update(int a, int b, S val, int k = 0, int l = 0, int r = -1) { if (r < 0) r = n; eval(k, l, r); if (b <= l || r <= a) return; if (a <= l && r <= b) { merge_functions(lazy[k], val); eval(k, l, r); } else { update(a, b, val, 2 * k + 1, l, (l + r) / 2); update(a, b, val, 2 * k + 2, (l + r) / 2, r); data[k] = merge_values(data[2 * k + 1], data[2 * k + 2]); } } T query(int a, int b, int k = 0, int l = 0, int r = -1) { if (r < 0) r = n; eval(k, l, r); if (b <= l || r <= a) return te; if (a <= l && r <= b) return data[k]; T vl = query(a, b, 2 * k + 1, l, (l + r) / 2); T vr = query(a, b, 2 * k + 2, (l + r) / 2, r); return merge_values(vl, vr); } T get(int p) { return query(p, p + 1); } }; int findFar(int st, vector<vector<Edge>> &g) { int N = g.size(); vector<int> dist(N, MOD); dist[st] = 0; queue<int> Q; Q.push(st); while (!Q.empty()) { int now = Q.front(); Q.pop(); for (auto e : g[now]) { if (dist[e.to] == MOD) { dist[e.to] = dist[now] + 1; Q.push(e.to); } } } int mat = 0; for (int i = 0; i < (N); ++i) if (dist[mat] < dist[i]) mat = i; return mat; } pair<int, int> getDiameter(vector<vector<Edge>> &g) { int st = findFar(0, g); st = findFar(st, g); int ed = findFar(st, g); return make_pair(st, ed); } void dfs(int now, int par, int col, vector<vector<Edge>> &g, vector<int> &dist) { dist[now] = col; for (auto e : g[now]) { if (e.to == par) continue; dfs(e.to, now, col ^ e.dist, g, dist); } } int main() { cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; vector<vector<Edge>> g(N); struct E { int from, to, col; E() {} E(int from, int to, int col) : from(from), to(to), col(col) {} }; vector<E> edges; for (int i = 0; i < (N - 1); ++i) { int a, b, c; cin >> a >> b >> c; a--; b--; g[a].emplace_back(Edge{b, c}); g[b].emplace_back(Edge{a, c}); edges.emplace_back(E{a, b, c}); } auto f = getDiameter(g); int st = f.first; int ed = f.second; const pair<int, int> unit = make_pair(0, 0); HeavyLightDecomposition hld1(N, g, st), hld2(N, g, ed); LazySegmentTree<pair<int, int>, int> seg1(N, unit, 0); LazySegmentTree<pair<int, int>, int> seg2(N, unit, 0); { vector<pair<int, int>> init(N); vector<int> dist(N); dfs(st, -1, 0, g, dist); for (int i = 0; i < (N); ++i) { if (dist[i] == 0) init[hld1.in[i]] = make_pair(hld1.dep[i], 0); else init[hld1.in[i]] = make_pair(0, hld1.dep[i]); } seg1.build(init); } { vector<pair<int, int>> init(N); vector<int> dist(N); dfs(ed, -1, 0, g, dist); for (int i = 0; i < (N); ++i) { if (dist[i] == 0) init[hld2.in[i]] = make_pair(hld2.dep[i], 0); else init[hld2.in[i]] = make_pair(0, hld2.dep[i]); } seg2.build(init); } int Q; cin >> Q; for (int q = 0; q < (Q); ++q) { int A; cin >> A; A--; { int now = 0; if (hld1.dep[edges[A].from] < hld1.dep[edges[A].to]) now = edges[A].to; else now = edges[A].from; hld1.update(now, 1, [&](int l, int r, int x) { seg1.update(l, r, x); }); } { int now = 0; if (hld2.dep[edges[A].from] < hld2.dep[edges[A].to]) now = edges[A].to; else now = edges[A].from; hld2.update(now, 1, [&](int l, int r, int x) { seg2.update(l, r, x); }); } auto res = max(seg1.query(0, N).first, seg2.query(0, N).first); cout << res << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; struct Edge { int to, nxt, dis; } e[1000005]; int n, m, num, x = 1, y = 1, tim, h[500005], dep[500005], q[500005]; int dfn[500005], out[500005], ans[500005], dis[500005]; int p[500005], mx[2][2000005], U[500005], V[500005], lazy[2000005]; void cmax(int &a, int b) { a = max(a, b); } void add(int u, int v, int d) { e[++num].to = v; e[num].dis = d; e[num].nxt = h[u]; h[u] = num; } void dfs(int u, int fa) { int v, i; dep[u] = dep[fa] + 1; for (i = h[u]; i; i = e[i].nxt) { v = e[i].to; if (v != fa) dfs(v, u); } } void dfs2(int u, int fa) { int v, i; dfn[u] = ++tim; dep[u] = dep[fa] + 1; for (i = h[u]; i; i = e[i].nxt) { v = e[i].to; if (v != fa) { dis[v] = (dis[u] + e[i].dis) & 1; dfs2(v, u); } } out[u] = tim; } void push_up(int ind) { mx[0][ind] = max(mx[0][ind << 1], mx[0][ind << 1 | 1]); mx[1][ind] = max(mx[1][ind << 1], mx[1][ind << 1 | 1]); } void push_down(int ind) { if (lazy[ind]) { lazy[ind << 1] = !lazy[ind << 1]; lazy[ind << 1 | 1] = !lazy[ind << 1 | 1]; swap(mx[0][ind << 1], mx[1][ind << 1]); swap(mx[0][ind << 1 | 1], mx[1][ind << 1 | 1]); lazy[ind] = 0; } } void build(int ind, int L, int R) { if (L == R) { mx[dis[p[L]]][ind] = dep[p[L]]; return; } int mid = (L + R) >> 1; build(ind << 1, L, mid); build(ind << 1 | 1, mid + 1, R); push_up(ind); } void upd(int ind, int L, int R, int l, int r) { if (l <= L && R <= r) { lazy[ind] = !lazy[ind]; swap(mx[0][ind], mx[1][ind]); return; } push_down(ind); int mid = (L + R) >> 1; if (l <= mid) upd(ind << 1, L, mid, l, r); if (r > mid) upd(ind << 1 | 1, mid + 1, R, l, r); push_up(ind); } void solve(int r) { int i, t; tim = 0; dis[r] = 0; memset(mx, 0, sizeof(mx)); memset(lazy, 0, sizeof(lazy)); dfs2(r, 0); for (i = 1; i <= n; i++) p[dfn[i]] = i; build(1, 1, n); for (i = 1; i <= m; i++) { t = dep[V[q[i]]] > dep[U[q[i]]] ? V[q[i]] : U[q[i]]; upd(1, 1, n, dfn[t], out[t]); cmax(ans[i], mx[0][1] - 1); } } int main() { ios::sync_with_stdio(false); int i, d; cin >> n; for (i = 1; i <= n - 1; i++) { cin >> U[i] >> V[i] >> d; add(U[i], V[i], d); add(V[i], U[i], d); } dfs(1, 0); for (i = 1; i <= n; i++) if (dep[i] > dep[x]) x = i; dfs(x, 0); for (i = 1; i <= n; i++) if (dep[i] > dep[y]) y = i; cin >> m; for (i = 1; i <= m; i++) cin >> q[i]; solve(x); solve(y); for (i = 1; i <= m; i++) cout << ans[i] << endl; return 0; }
#include <bits/stdc++.h> namespace atcoder { namespace internal { int ceil_pow2(int n) { int x = 0; while ((1U << x) < (unsigned int)(n)) x++; return x; } int bsf(unsigned int n) { return __builtin_ctz(n); } } // namespace internal } // namespace atcoder namespace atcoder { template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()> struct lazy_segtree { public: lazy_segtree() : lazy_segtree(0) {} lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {} lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) { log = internal::ceil_pow2(_n); size = 1 << log; d = std::vector<S>(2 * size, e()); lz = std::vector<F>(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) { update(i); } } void set(int p, S x) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = x; for (int i = 1; i <= log; i++) update(p >> i); } S get(int p) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); return d[p]; } S prod(int l, int r) { assert(0 <= l && l <= r && r <= _n); if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push(r >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S all_prod() { return d[1]; } void apply(int p, F f) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = mapping(f, d[p]); for (int i = 1; i <= log; i++) update(p >> i); } void apply(int l, int r, F f) { assert(0 <= l && l <= r && r <= _n); if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } template <bool (*g)(S)> int max_right(int l) { return max_right(l, [](S x) { return g(x); }); } template <class G> int max_right(int l, G g) { assert(0 <= l && l <= _n); assert(g(e())); if (l == _n) return _n; l += size; for (int i = log; i >= 1; i--) push(l >> i); S sm = e(); do { while (l % 2 == 0) l >>= 1; if (!g(op(sm, d[l]))) { while (l < size) { push(l); l = (2 * l); if (g(op(sm, d[l]))) { sm = op(sm, d[l]); l++; } } return l - size; } sm = op(sm, d[l]); l++; } while ((l & -l) != l); return _n; } template <bool (*g)(S)> int min_left(int r) { return min_left(r, [](S x) { return g(x); }); } template <class G> int min_left(int r, G g) { assert(0 <= r && r <= _n); assert(g(e())); if (r == 0) return 0; r += size; for (int i = log; i >= 1; i--) push((r - 1) >> i); S sm = e(); do { r--; while (r > 1 && (r % 2)) r >>= 1; if (!g(op(d[r], sm))) { while (r < size) { push(r); r = (2 * r + 1); if (g(op(d[r], sm))) { sm = op(d[r], sm); r--; } } return r + 1 - size; } sm = op(d[r], sm); } while ((r & -r) != r); return 0; } private: int _n, size, log; std::vector<S> d; std::vector<F> lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; } // namespace atcoder using namespace std; using namespace atcoder; using ll = long long; using P = pair<int, int>; using VI = vector<int>; using VVI = vector<VI>; struct HLD { std::vector<std::vector<int>>& to; int root, n; std::vector<int> sz, parent, depth, idx, ridx, head; HLD(std::vector<std::vector<int>>& to, int root = 0) : to(to), root(root), n(to.size()), sz(n), parent(n), depth(n), idx(n), ridx(n), head(n) { init_tree_data(root); int x = 0; assign_idx(root, root, x); } void init_tree_data(int u, int p = -1, int d = 0) { parent[u] = p; depth[u] = d; int s = 1; for (int v : to[u]) { if (v == p) continue; init_tree_data(v, u, d + 1); s += sz[v]; } sz[u] = s; } void assign_idx(int u, int h, int& nxt, int p = -1) { head[u] = h; idx[u] = nxt++; if (sz[u] == 1) { ridx[u] = nxt; return; } int mxsize = 0; int mi; for (int v : to[u]) { if (v == p) continue; if (sz[v] > mxsize) { mxsize = sz[v]; mi = v; } } assign_idx(mi, h, nxt, u); for (int v : to[u]) { if (v == p || v == mi) continue; assign_idx(v, v, nxt, u); } ridx[u] = nxt; } }; struct S { int even, odd; }; S op(S x, S y) { return {max(x.even, y.even), max(x.odd, y.odd)}; } S e() { return {-1, -1}; } S mapping(bool f, S x) { if (f) return {x.odd, x.even}; else return x; } bool composition(bool f, bool g) { return f ^ g; } bool id() { return false; } struct E { int u, v, state; }; VVI to; P dfs(int u, int p = -1, int depth = 0) { P ret = {u, depth}; for (int v : to[u]) { if (v == p) continue; P r = dfs(v, u, depth + 1); if (r.second > ret.second) ret = r; } return ret; } int main() { ios::sync_with_stdio(false); cin.tie(0); int n; cin >> n; to.resize(n); vector<E> es(n - 1); for (int i = 0; i < (n - 1); ++i) { int u, v, t; cin >> u >> v >> t; --u, --v; es[i] = {u, v, t}; to[u].push_back(v); to[v].push_back(u); } int m; cin >> m; VI query(m); for (int i = 0; i < (m); ++i) { cin >> query[i]; query[i]--; } VI ab(2); ab[0] = dfs(0).first; ab[1] = dfs(ab[0]).first; VVI ans(2, VI(m)); for (int tt = 0; tt < (2); ++tt) { int a = ab[tt]; HLD hld(to, a); VI is_odd(n); for (int i = 0; i < (n - 1); ++i) { int u = es[i].u, v = es[i].v, s = es[i].state; if (hld.parent[u] == v) { swap(u, v); swap(es[i].u, es[i].v); } is_odd[v] = s; } queue<int> que; que.push(a); while (!que.empty()) { int u = que.front(); que.pop(); for (int v : to[u]) { if (v == hld.parent[u]) continue; is_odd[v] ^= is_odd[u]; que.push(v); } } vector<S> init_vec(n); for (int i = 0; i < (n); ++i) { if (is_odd[i]) { init_vec[hld.idx[i]] = {-1, hld.depth[i]}; } else { init_vec[hld.idx[i]] = {hld.depth[i], -1}; } } lazy_segtree<S, op, e, bool, mapping, composition, id> seg(init_vec); for (int i = 0; i < (m); ++i) { int ei = query[i]; int v = es[ei].v; int vin = hld.idx[v], vout = hld.ridx[v]; seg.apply(vin, vout, true); ans[tt][i] = seg.all_prod().even; } } for (int i = 0; i < (m); ++i) cout << max(ans[0][i], ans[1][i]) << '\n'; }
#include <bits/stdc++.h> template <class T, class U> inline bool smin(T &x, const U &y) { return y < x ? x = y, 1 : 0; } template <class T, class U> inline bool smax(T &x, const U &y) { return x < y ? x = y, 1 : 0; } using LL = long long; using PII = std::pair<int, int>; constexpr int N(5e5 + 5); struct Info { int c, len, d[2][2], r[2]; Info() : c(0), len(0) { d[0][0] = 0, d[0][1] = -1e9; d[1][0] = 0, d[1][1] = -1e9; r[0] = r[1] = -1e9; } void reverse() { std::swap(d[0][0], d[1][0]); std::swap(d[0][1], d[1][1]); } Info &compress(Info a, Info b) { c = a.c ^ b.c; len = a.len + b.len; d[0][0] = std::max(a.d[0][0], a.len + b.d[0][a.c]); d[0][1] = std::max(a.d[0][1], a.len + b.d[0][!a.c]); d[1][0] = std::max(b.d[1][0], b.len + a.d[1][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[1][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[1][0] + b.d[0][0], a.d[1][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[1][0] + b.d[0][1], a.d[1][1] + b.d[0][0]}); return *this; } Info &rake(Info a, Info b) { c = b.c; len = b.len; d[0][0] = std::max(a.d[0][0], b.d[0][0]); d[0][1] = std::max(a.d[0][1], b.d[0][1]); d[1][0] = std::max(b.d[1][0], b.len + a.d[0][b.c]); d[1][1] = std::max(b.d[1][1], b.len + a.d[0][!b.c]); r[0] = std::max( {a.r[0], b.r[0], a.d[0][0] + b.d[0][0], a.d[0][1] + b.d[0][1]}); r[1] = std::max( {a.r[1], b.r[1], a.d[0][0] + b.d[0][1], a.d[0][1] + b.d[0][0]}); return *this; } }; struct SplayTree { static SplayTree *null; SplayTree *ch[3], *fa; bool rev; Info info; SplayTree() : rev(false) { static bool init = true; if (init) { init = false; null = new SplayTree; null->ch[0] = null->ch[1] = null->ch[2] = null->fa = null; } ch[0] = ch[1] = ch[2] = fa = null; } bool notRoot() const { return fa->ch[0] == this || fa->ch[1] == this; } void reverse() { rev ^= 1; std::swap(ch[0], ch[1]); info.reverse(); } bool dir() const { return fa->ch[1] == this; } void sch(int d, SplayTree *c) { ch[d] = c, c->fa = this; } void rotate() { SplayTree *p = fa; bool d = dir(); fa = p->fa; if (fa != null) { fa->ch[fa->ch[2] == p ? 2 : p->dir()] = this; } p->sch(d, ch[!d]), sch(!d, p); p->pushup(); } void splay() { static SplayTree *s[N], **t; t = s; for (auto x = this; x->notRoot(); x = x->fa) *++t = x->fa; while (t != s) (*t--)->pushdown(); for (pushdown(); notRoot(); rotate()) { if (fa->notRoot()) { (fa->dir() == dir() ? fa : this)->rotate(); } } pushup(); } virtual void pushup() {} virtual void pushdown() {} }; SplayTree *SplayTree::null; struct RakeTree : SplayTree { void pushup() { info.rake(ch[0]->info, Info().rake(ch[2]->info, ch[1]->info)); } }; struct CompressTree : SplayTree { void pushup() { info.compress(ch[0]->info, Info().rake(ch[2]->info, ch[1]->info)); } void pushdown() { if (rev) { rev = false; ch[0]->reverse(), ch[1]->reverse(); } } void access() { splay(); if (ch[1] != null) { auto r = new RakeTree; r->sch(0, ch[2]), r->sch(2, ch[1]), r->pushup(); ch[1] = null, sch(2, r), pushup(); } for (; fa != null; rotate()) { fa->splay(); SplayTree *m = fa, *p = m->fa; assert(p != null); p->splay(); if (p->ch[1] != null) { m->sch(2, p->ch[1]); m->pushup(); } else { if (m->ch[0] == null) { p->sch(2, m->ch[1]); } else if (m->ch[1] == null) { p->sch(2, m->ch[0]); } else { auto x = m->ch[0]; x->fa = null; while (x->pushdown(), x->ch[1] != null) x = x->ch[1]; x->splay(); p->sch(2, x); x->sch(1, m->ch[1]); x->pushup(); } delete m; } p->sch(1, this); p->pushup(); } pushup(); } void evert() { access(), reverse(), pushdown(); } }; void link(CompressTree *x, CompressTree *y, int c) { x->access(), y->evert(); auto e = new CompressTree; e->info.len = 1, e->info.c = c; x->sch(1, y), y->sch(0, e); y->pushup(), x->pushup(); } int main() { std::ios::sync_with_stdio(false); std::cin.tie(nullptr); int n, m; std::cin >> n; CompressTree *t = new CompressTree[n + 1]; assert(SplayTree::null); std::vector<int> u(n - 1), v(n - 1); for (int i = 0, c; i < n - 1; i++) { std::cin >> u[i] >> v[i] >> c; link(t + u[i], t + v[i], c); } std::cin >> m; while (m--) { int i; std::cin >> i; i--; t[u[i]].evert(), t[v[i]].access(); t[u[i]].ch[1]->info.c ^= 1; t[u[i]].pushup(); t[v[i]].pushup(); std::cout << t[v[i]].info.r[0] << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2000005; int n, m, rt, dep[N], dfn[N][2], f[N][2], dis[N], rf[N][2], cnt; int v[N], nxt[N], head[N], w[N], id[N][2], s[2][N][2], tag[2][N]; void dfs(int x, int fa) { dfn[x][1] = ++cnt, f[cnt][1] = x; for (int i = head[x]; i > 0; i = nxt[i]) { if (v[i] == fa) continue; dis[v[i]] = dis[x] + w[i]; dep[v[i]] = dep[x] + 1, dfs(v[i], x); if (i < n) id[i][1] = v[i]; else id[i - n][1] = v[i]; } rf[x][1] = cnt; } void build(int x, int l, int r, int d) { if (l == r) { s[d][x][dis[f[l][d]] & 1] = dep[f[l][d]]; return; } int mid = (l + r) >> 1; build(x << 1, l, mid, d), build(x << 1 | 1, mid + 1, r, d); s[d][x][0] = max(s[d][x << 1][0], s[d][x << 1 | 1][0]); s[d][x][1] = max(s[d][x << 1][1], s[d][x << 1 | 1][1]); } void pushdown(int x, int l, int r, int d) { if (!tag[d][x]) return; swap(s[d][x << 1][0], s[d][x << 1][1]); swap(s[d][x << 1 | 1][0], s[d][x << 1 | 1][1]); tag[d][x << 1] ^= 1, tag[d][x << 1 | 1] ^= 1; tag[d][x] = 0; } void modify(int x, int l, int r, int L, int R, int d) { if (l >= L && R >= r) { tag[d][x] ^= 1; swap(s[d][x][0], s[d][x][1]); return; } pushdown(x, l, r, d); int mid = (l + r) >> 1; if (L <= mid) modify(x << 1, l, mid, L, R, d); if (R > mid) modify(x << 1 | 1, mid + 1, r, L, R, d); s[d][x][0] = max(s[d][x << 1][0], s[d][x << 1 | 1][0]); s[d][x][1] = max(s[d][x << 1][1], s[d][x << 1 | 1][1]); } int main() { scanf("%d", &n); for (int i = 1; i < n; i++) { scanf("%d%d", &v[i], &v[i + n]); nxt[i] = head[v[i + n]], head[v[i + n]] = i; nxt[i + n] = head[v[i]], head[v[i]] = i + n; scanf("%d", &w[i]), w[i + n] = w[i]; } dfs(1, 0), rt = 1, cnt = 0; for (int i = 1; i <= n; i++) if (dep[rt] < dep[i]) rt = i; dep[rt] = dis[rt] = 0, dfs(rt, 0); for (int i = 1; i <= n; i++) dfn[i][0] = dfn[i][1], rf[i][0] = rf[i][1]; for (int i = 1; i <= n; i++) id[i][0] = id[i][1], f[i][0] = f[i][1]; build(1, 1, n, 0), cnt = 0; for (int i = 1; i <= n; i++) if (dep[rt] < dep[i]) rt = i; dep[rt] = dis[rt] = 0, dfs(rt, 0), build(1, 1, n, 1); scanf("%d", &m); for (int i = 1; i <= m; i++) { int x; scanf("%d", &x); modify(1, 1, n, dfn[id[x][0]][0], rf[id[x][0]][0], 0); modify(1, 1, n, dfn[id[x][1]][1], rf[id[x][1]][1], 1); printf("%d\n", max(s[0][1][0], s[1][1][0])); } }
#include <bits/stdc++.h> namespace atcoder { namespace internal { int ceil_pow2(int n) { int x = 0; while ((1U << x) < (unsigned int)(n)) x++; return x; } int bsf(unsigned int n) { return __builtin_ctz(n); } } // namespace internal } // namespace atcoder namespace atcoder { template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()> struct lazy_segtree { public: lazy_segtree() : lazy_segtree(0) {} lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {} lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) { log = internal::ceil_pow2(_n); size = 1 << log; d = std::vector<S>(2 * size, e()); lz = std::vector<F>(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) { update(i); } } void set(int p, S x) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = x; for (int i = 1; i <= log; i++) update(p >> i); } S get(int p) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); return d[p]; } S prod(int l, int r) { assert(0 <= l && l <= r && r <= _n); if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push(r >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S all_prod() { return d[1]; } void apply(int p, F f) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = mapping(f, d[p]); for (int i = 1; i <= log; i++) update(p >> i); } void apply(int l, int r, F f) { assert(0 <= l && l <= r && r <= _n); if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } template <bool (*g)(S)> int max_right(int l) { return max_right(l, [](S x) { return g(x); }); } template <class G> int max_right(int l, G g) { assert(0 <= l && l <= _n); assert(g(e())); if (l == _n) return _n; l += size; for (int i = log; i >= 1; i--) push(l >> i); S sm = e(); do { while (l % 2 == 0) l >>= 1; if (!g(op(sm, d[l]))) { while (l < size) { push(l); l = (2 * l); if (g(op(sm, d[l]))) { sm = op(sm, d[l]); l++; } } return l - size; } sm = op(sm, d[l]); l++; } while ((l & -l) != l); return _n; } template <bool (*g)(S)> int min_left(int r) { return min_left(r, [](S x) { return g(x); }); } template <class G> int min_left(int r, G g) { assert(0 <= r && r <= _n); assert(g(e())); if (r == 0) return 0; r += size; for (int i = log; i >= 1; i--) push((r - 1) >> i); S sm = e(); do { r--; while (r > 1 && (r % 2)) r >>= 1; if (!g(op(d[r], sm))) { while (r < size) { push(r); r = (2 * r + 1); if (g(op(d[r], sm))) { sm = op(d[r], sm); r--; } } return r + 1 - size; } sm = op(d[r], sm); } while ((r & -r) != r); return 0; } private: int _n, size, log; std::vector<S> d; std::vector<F> lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; } // namespace atcoder using namespace std; using Int = long long; using Real = long double; using CP = complex<Real>; using P = pair<Int, Int>; const Int MOD = 1000000007; const Int MOD2 = 998244353; const Int LINF = (1LL << 60); const int INF = (1000000007); const Real EPS = 1e-10; const long double PI = 3.141592653589793238462643383279502884L; vector<P> edge[550000]; void dfs(int x, vector<int>& dep, int last = -1) { if (last == -1) dep[x] = 0; for (auto [to, _] : edge[x]) { if (to == last) continue; dep[to] = dep[x] + 1; dfs(to, dep, x); } } int n; int u[550000]; int v[550000]; int t[550000]; P op(P x, P y) { if (x.first == INF) return y; if (y.first == INF) return x; return {max({x.first, x.second, y.first, y.second}), min({x.first, x.second, y.first, y.second})}; } P e() { return {INF, INF}; } P mapping(bool x, P y) { if (y.first == INF) return y; return x ? P(-y.first, -y.second) : y; } bool composition(bool x, bool y) { return x ^ y; } bool id() { return false; } using lazy_seg = atcoder::lazy_segtree<P, op, e, bool, mapping, composition, id>; struct Euler { lazy_seg seg; vector<int> in, out; vector<P> tmp; int p; void dfs2(int v, int last = -1, int dep = 0, int fliped = 1) { in[v] = p++; tmp[in[v]] = P(dep * fliped, dep * fliped); for (auto [to, ind] : edge[v]) { if (to == last) continue; dfs2(to, v, dep + 1, fliped * (t[ind] ? -1 : 1)); } out[v] = p; } Euler(int v) : p(0), in(n + 1), out(n + 1), tmp(n) { dfs2(v); seg = lazy_seg(tmp); } void flip(int u, int v) { if (in[u] < in[v]) swap(u, v); seg.apply(in[u], out[u], true); } int get_max() { auto res = seg.all_prod(); return max(res.first, res.second); } }; int main() { scanf("%d", &n); for (int i = 1; i <= n - 1; i++) { scanf("%d%d%d", &u[i], &v[i], &t[i]); edge[u[i]].emplace_back(v[i], i); edge[v[i]].emplace_back(u[i], i); } vector<int> dep1(n + 1), dep2(n + 1); dfs(1, dep2); int farest1 = 1; for (int i = 1; i <= n; i++) { if (dep2[i] > dep2[farest1]) farest1 = i; } dfs(farest1, dep1); int farest2 = 1; for (int i = 1; i <= n; i++) if (dep1[i] > dep1[farest2]) farest2 = i; dfs(farest2, dep2); Euler tree1(farest1), tree2(farest2); int m; scanf("%d", &m); for (int i = 0; i < m; i++) { int q; scanf("%d", &q); tree1.flip(u[q], v[q]); tree2.flip(u[q], v[q]); printf("%d\n", max(tree1.get_max(), tree2.get_max())); } return 0; }
#include <bits/stdc++.h> using namespace std; const int maxN = 500005; int N, Q; int lnk[maxN]; int pre[maxN << 1], tgt[maxN << 1], cnt; int val[maxN << 1]; int pos[maxN]; void add_E(int u, int v, int c) { pre[++cnt] = lnk[u], tgt[cnt] = v, val[cnt] = c, lnk[u] = cnt; } int dep[maxN], wdep[maxN]; int Tin[maxN], Tout[maxN]; int dfn[maxN << 1], idx; void dfs(int x, int f) { dfn[++idx] = x; Tin[x] = idx; for (int e = lnk[x]; e; e = pre[e]) if (tgt[e] != f) pos[(e + 1) >> 1] = tgt[e], dep[tgt[e]] = dep[x] + 1, wdep[tgt[e]] = wdep[x] + val[e], dfs(tgt[e], x), dfn[++idx] = x; Tout[x] = idx; } int W[maxN << 3][2], M[maxN << 3], LM[maxN << 3][2], MR[maxN << 3][2], LMR[maxN << 3][2], Lzy[maxN << 3]; void push_up(int x) { M[x] = max(M[x << 1], M[x << 1 | 1]); for (int k = 0; k < 2; k++) { W[x][k] = max(W[x << 1][k], W[x << 1 | 1][k]); LM[x][k] = max(LM[x << 1][k], LM[x << 1 | 1][k]); MR[x][k] = max(MR[x << 1][k], MR[x << 1 | 1][k]); LMR[x][k] = max(LMR[x << 1][k], LMR[x << 1 | 1][k]); LM[x][k] = max(LM[x][k], W[x << 1][k] + M[x << 1 | 1]); MR[x][k] = max(MR[x][k], M[x << 1] + W[x << 1 | 1][k]); } for (int k1 = 0; k1 < 2; k1++) for (int k2 = 0; k2 < 2; k2++) LMR[x][k1 ^ k2] = max(LMR[x][k1 ^ k2], max(LM[x << 1][k1] + W[x << 1 | 1][k2], W[x << 1][k1] + MR[x << 1 | 1][k2])); } void Rev(int x) { swap(W[x][0], W[x][1]); swap(LM[x][0], LM[x][1]); swap(MR[x][0], MR[x][1]); Lzy[x] ^= 1; } void push_down(int x) { if (!Lzy[x]) return; Rev(x << 1); Rev(x << 1 | 1); Lzy[x] = 0; } void Build(int x, int l, int r) { if (l == r) { int k = wdep[dfn[l]] & 1; W[x][k] = dep[dfn[l]]; M[x] = -2 * dep[dfn[l]]; LM[x][k] = MR[x][k] = -dep[dfn[l]]; W[x][k ^ 1] = -0x3f3f3f3f; LM[x][k ^ 1] = MR[x][k ^ 1] = -0x3f3f3f3f; return; } int mid = (l + r) >> 1; Build(x << 1, l, mid); Build(x << 1 | 1, mid + 1, r); push_up(x); } void Update(int x, int l, int r, int L, int R) { if (L <= l && r <= R) { Rev(x); return; } int mid = (l + r) >> 1; push_down(x); if (L <= mid) Update(x << 1, l, mid, L, R); if (R > mid) Update(x << 1 | 1, mid + 1, r, L, R); push_up(x); } int main() { scanf("%d", &N); for (int i = 1; i < N; i++) { int u, v, c; scanf("%d%d%d", &u, &v, &c); add_E(u, v, c); add_E(v, u, c); } dfs(1, 0); Build(1, 1, idx); scanf("%d", &Q); while (Q--) { int d; scanf("%d", &d); Update(1, 1, idx, Tin[pos[d]], Tout[pos[d]]); printf("%d\n", LMR[1][0]); } }
#include <bits/stdc++.h> #pragma optimize("SEX_ON_THE_BEACH") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("O3") #pragma GCC optimize("Ofast") #pragma GCC optimize("fast-math") #pragma GCC optimize("no-stack-protector") #pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native") using ll = long long int; using ull = unsigned long long int; using dd = double; using ldd = long double; namespace someUsefull { template <typename T1, typename T2> inline void checkMin(T1& a, T2 b) { if (a > b) a = b; } template <typename T1, typename T2> inline void checkMax(T1& a, T2 b) { if (a < b) a = b; } const int _bitfunctions_size_ = 16; const int _bitfunctions_mask_ = (1 << _bitfunctions_size_) - 1; char* _bits_count_; inline void _build_bits_count_() { _bits_count_ = new char[1 << _bitfunctions_size_]; for (int i = 1; i < (1 << _bitfunctions_size_); ++i) { _bits_count_[i] = _bits_count_[i >> 1]; if (i & 1) ++_bits_count_[i]; } } template <typename T1 = char, typename T2 = int> inline T1 popcnt(T2 x) { T1 ans = 0; while (x) { ans += _bits_count_[x & _bitfunctions_mask_]; x >>= _bitfunctions_size_; } return ans; } } // namespace someUsefull namespace operators { template <typename T1, typename T2> std::istream& operator>>(std::istream& in, std::pair<T1, T2>& x) { in >> x.first >> x.second; return in; } template <typename T1, typename T2> std::ostream& operator<<(std::ostream& out, std::pair<T1, T2> x) { out << x.first << " " << x.second; return out; } template <typename T1> std::istream& operator>>(std::istream& in, std::vector<T1>& x) { for (auto& i : x) in >> i; return in; } template <typename T1> std::ostream& operator<<(std::ostream& out, std::vector<T1>& x) { for (auto& i : x) out << i << " "; return out; } } // namespace operators using namespace std; using namespace operators; using namespace someUsefull; vector<vector<int>> gr; vector<pair<int, int>> ed; vector<int> d; void dfs(int v, int _d = 0, int p = -1) { d[v] = _d; for (int to : gr[v]) { if (to != p) dfs(to, _d + 1, v); } } struct Tree { const int _size = 1 << 19; int n, t; vector<pair<int, int>> tree; vector<int> upd; vector<int> d; vector<int> pre; vector<int> tin, tout, tos; void dfs(int v, int _d = 0, int p = -1) { d[v] = _d; pre[v] = p; tin[v] = tos.size(); tos.push_back(v); for (int to : gr[v]) { if (to != p) dfs(to, _d + 1, v); } tout[v] = tos.size(); } pair<int, int> merge(pair<int, int> a, pair<int, int> b) { return {max(a.first, b.first), max(a.second, b.second)}; } Tree(int v) { tree.resize(_size << 1, {0, 0}); upd.resize(_size << 1, 0); n = gr.size(); t = 0; d.resize(n); tin.resize(n); tout.resize(n); pre.resize(n); 0; ; dfs(v); 0; ; for (int i = 0; i < n; ++i) tree[_size + i].first = d[tos[i]]; for (int i = _size - 1; i > 0; --i) tree[i] = merge(tree[i << 1], tree[i << 1 | 1]); } void change(int v) { upd[v] ^= 1; swap(tree[v].first, tree[v].second); } void push(int v) { if (!upd[v]) return; change(v << 1); change(v << 1 | 1); upd[v] = 0; } void update(int v, int l, int r, int fl, int fr) { if (r <= l || r <= fl || fr <= l) return; if (fl <= l && r <= fr) { change(v); return; } push(v); update(v << 1, l, (r + l) >> 1, fl, fr); update(v << 1 | 1, (r + l) >> 1, r, fl, fr); tree[v] = merge(tree[v << 1], tree[v << 1 | 1]); } int add(int a, int b) { if (pre[a] != b) swap(a, b); update(1, 0, _size, tin[a], tout[a]); return tree[1].first; } }; void solve(int test) { int n; cin >> n; gr.resize(n); vector<int> type(n - 1); for (int i = 0; i < n - 1; ++i) { int a, b; cin >> a >> b >> type[i]; --a; --b; ed.push_back({a, b}); gr[a].push_back(b); gr[b].push_back(a); } d.resize(n); d.assign(n, -1); dfs(0); int v = 0; for (int i = 0; i < n; ++i) if (d[v] < d[i]) v = i; dfs(v); int L = v; int R = 0; for (int i = 0; i < n; ++i) if (d[R] < d[i]) R = i; 0; ; 0; ; Tree LT(L), RT(R); 0; ; for (int i = 0; i < n - 1; ++i) { if (type[i]) LT.add(ed[i].first, ed[i].second), RT.add(ed[i].first, ed[i].second); } int m; cin >> m; for (int i = 0; i < m; ++i) { int x; cin >> x; --x; int ans = 0; checkMax(ans, LT.add(ed[x].first, ed[x].second)); checkMax(ans, RT.add(ed[x].first, ed[x].second)); cout << ans << '\n'; } } signed main() { ios_base::sync_with_stdio(false); cout.tie(0); cin.tie(0); _build_bits_count_(); cout << setprecision(12) << fixed; int t = 1; for (int i = 0; i < t; ++i) { 0; ; solve(i + 1); } return 0; }
#include <bits/stdc++.h> using namespace std; template <typename T> inline bool upmin(T &x, T y) { return y < x ? x = y, 1 : 0; } template <typename T> inline bool upmax(T &x, T y) { return x < y ? x = y, 1 : 0; } const long double eps = 1e-11; const long double pi = acos(-1); const int oo = 1 << 30; const long long loo = 1ll << 62; const int mods = 998244353; const int MAXN = 1000005; const int INF = 0x3f3f3f3f; inline long long read() { long long f = 1, x = 0; char c = getchar(); while (c < '0' || c > '9') { if (c == '-') f = -1; c = getchar(); } while (c >= '0' && c <= '9') { x = (x << 3) + (x << 1) + (c ^ 48); c = getchar(); } return x * f; } int edgenum = 1, head[MAXN], to[MAXN], nxt[MAXN], c[MAXN]; int DFN = 0, low[MAXN], lowu[MAXN], lowv[MAXN], dfn[MAXN], dfnu[MAXN], dfnv[MAXN], y[MAXN], yu[MAXN], yv[MAXN], dep[MAXN], w[MAXN], id[MAXN]; void add(int u, int v, int C) { edgenum++, to[edgenum] = v, c[edgenum] = C, nxt[edgenum] = head[u], head[u] = edgenum; } void dfs(int x, int father) { id[dfn[x] = ++DFN] = x, dep[x] = dep[father] + 1; for (int i = head[x]; i; i = nxt[i]) { if (to[i] == father) continue; w[to[i]] = w[x] ^ c[i]; y[i >> 1] = to[i]; dfs(to[i], x); } low[x] = DFN; } struct Segment_Tree { int mx0[MAXN << 2], mx1[MAXN << 2], tag[MAXN << 2]; void down(int x) { if (tag[x]) swap(mx0[x << 1], mx1[x << 1]), swap(mx0[x << 1 | 1], mx1[x << 1 | 1]), tag[x << 1] ^= 1, tag[x << 1 | 1] ^= 1, tag[x] = 0; } void build(int x, int l, int r) { if (l == r) { if (w[id[l]]) mx0[x] = -1, mx1[x] = dep[id[l]]; else mx0[x] = dep[id[l]], mx1[x] = -1; return; } int mid = (l + r) >> 1; build(x << 1, l, mid); build(x << 1 | 1, mid + 1, r); mx0[x] = max(mx0[x << 1], mx0[x << 1 | 1]); mx1[x] = max(mx1[x << 1], mx1[x << 1 | 1]); } void reverse(int x, int l, int r, int L, int R) { if (l >= L && r <= R) { swap(mx0[x], mx1[x]); tag[x] ^= 1; return; } down(x); int mid = (l + r) >> 1; if (R <= mid) reverse(x << 1, l, mid, L, R); else if (L > mid) reverse(x << 1 | 1, mid + 1, r, L, R); else reverse(x << 1, l, mid, L, mid), reverse(x << 1 | 1, mid + 1, r, mid + 1, R); mx0[x] = max(mx0[x << 1], mx0[x << 1 | 1]); mx1[x] = max(mx1[x << 1], mx1[x << 1 | 1]); } } Tu, Tv; signed main() { int n = read(), U = 0, V = 0; for (int i = 1; i < n; i++) { int u = read(), v = read(), c = read(); add(u, v, c), add(v, u, c); } DFN = 0, w[1] = 0, dfs(1, 0); for (int i = 1; i <= n; i++) if (dep[i] > dep[U]) U = i; DFN = 0, w[U] = 0, dfs(U, 0); for (int i = 1; i <= n; i++) dfnu[i] = dfn[i], lowu[i] = low[i], yu[i] = y[i]; Tu.build(1, 1, n); for (int i = 1; i <= n; i++) if (dep[i] > dep[V]) V = i; DFN = 0, w[V] = 0, dfs(V, 0); for (int i = 1; i <= n; i++) dfnv[i] = dfn[i], lowv[i] = low[i], yv[i] = y[i]; Tv.build(1, 1, n); int Case = read(); while (Case--) { int t = read(), x = yu[t], y = yv[t]; Tu.reverse(1, 1, n, dfnu[x], lowu[x]); Tv.reverse(1, 1, n, dfnv[y], lowv[y]); printf("%d\n", max(Tu.mx0[1], Tv.mx0[1]) - 1); } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 10; const int inf = 5e8; int n, dfn[N], low[N], seq[N], tim, col[N], dep[N], mx[N << 2], mxn[N << 2][2], mxl[N << 2][2], mxr[N << 2][2], mnm[N << 2], sub[N]; bool s[N], tag[N << 2]; vector<pair<int, int> > E[N]; void dfs(int u, int ff) { seq[dfn[u] = ++tim] = u; dep[u] = dep[ff] + 1; for (auto e : E[u]) { int v = e.first; if (v != ff) sub[e.second] = v, s[v] = s[u] ^ col[e.second], dfs(v, u), seq[++tim] = u; } low[u] = tim; } void chkmax(int &a, int b) { a = max(a, b); } void up(int x) { mx[x] = mxn[x][0] = mxn[x][1] = mxl[x][0] = mxl[x][1] = mxr[x][0] = mxr[x][1] = -inf; mnm[x] = min(mnm[(x << 1)], mnm[(x << 1 | 1)]); mx[x] = max(mx[(x << 1)], mx[(x << 1 | 1)]); for (int i = 0; i < 2; i++) { chkmax(mxn[x][i], max(mxn[(x << 1)][i], mxn[(x << 1 | 1)][i])); chkmax(mxl[x][i], max(mxl[(x << 1)][i], max(mxl[(x << 1 | 1)][i], mxn[(x << 1 | 1)][i] - 2 * mnm[(x << 1)]))); chkmax(mxr[x][i], max(mxr[(x << 1)][i], max(mxr[(x << 1 | 1)][i], mxn[(x << 1)][i] - 2 * mnm[(x << 1 | 1)]))); } for (int i = 0; i < 2; i++) chkmax(mx[x], max(mxr[(x << 1)][i] + mxn[(x << 1 | 1)][i], mxn[(x << 1)][i] + mxl[(x << 1 | 1)][i])); } void mdf(int x) { swap(mxn[x][0], mxn[x][1]); swap(mxl[x][0], mxl[x][1]); swap(mxr[x][0], mxr[x][1]); tag[x] ^= 1; } void down(int x) { if (tag[x]) mdf((x << 1)), mdf((x << 1 | 1)), tag[x] = 0; } void build(int x = 1, int l = 1, int r = tim) { if (l == r) { mnm[x] = dep[seq[l]]; if (dfn[seq[l]] == l) { bool f = s[seq[l]]; int d = dep[seq[l]]; mxn[x][f] = d; mxl[x][f] = mxr[x][f] = -d; mx[x] = 0; mxn[x][f ^ 1] = mxl[x][f ^ 1] = mxr[x][f ^ 1] = -inf; } else { mx[x] = mxn[x][0] = mxn[x][1] = mxl[x][0] = mxl[x][1] = mxr[x][0] = mxr[x][1] = -inf; } return; } int mid = (l + r) >> 1; build((x << 1), l, mid); build((x << 1 | 1), mid + 1, r); up(x); } void modify(int L, int R, int x = 1, int l = 1, int r = tim) { if (L <= l && r <= R) return mdf(x); down(x); int mid = (l + r) >> 1; if (L <= mid) modify(L, R, (x << 1), l, mid); if (R > mid) modify(L, R, (x << 1 | 1), mid + 1, r); up(x); } int main() { ios::sync_with_stdio(0); cin.tie(0); cin >> n; for (int i = 1, u, v; i < n; i++) { cin >> u >> v >> col[i]; E[u].push_back(make_pair(v, i)); E[v].push_back(make_pair(u, i)); } dfs(1, 0); build(); int m; cin >> m; while (m--) { int id; cin >> id; int u = sub[id]; modify(dfn[u], low[u]); cout << mx[1] << '\n'; } return 0; }
#include <bits/stdc++.h> namespace atcoder { namespace internal { int ceil_pow2(int n) { int x = 0; while ((1U << x) < (unsigned int)(n)) x++; return x; } int bsf(unsigned int n) { return __builtin_ctz(n); } } // namespace internal } // namespace atcoder namespace atcoder { template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()> struct lazy_segtree { public: lazy_segtree() : lazy_segtree(0) {} lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {} lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) { log = internal::ceil_pow2(_n); size = 1 << log; d = std::vector<S>(2 * size, e()); lz = std::vector<F>(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) { update(i); } } void set(int p, S x) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = x; for (int i = 1; i <= log; i++) update(p >> i); } S get(int p) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); return d[p]; } S prod(int l, int r) { assert(0 <= l && l <= r && r <= _n); if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push(r >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S all_prod() { return d[1]; } void apply(int p, F f) { assert(0 <= p && p < _n); p += size; for (int i = log; i >= 1; i--) push(p >> i); d[p] = mapping(f, d[p]); for (int i = 1; i <= log; i++) update(p >> i); } void apply(int l, int r, F f) { assert(0 <= l && l <= r && r <= _n); if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } template <bool (*g)(S)> int max_right(int l) { return max_right(l, [](S x) { return g(x); }); } template <class G> int max_right(int l, G g) { assert(0 <= l && l <= _n); assert(g(e())); if (l == _n) return _n; l += size; for (int i = log; i >= 1; i--) push(l >> i); S sm = e(); do { while (l % 2 == 0) l >>= 1; if (!g(op(sm, d[l]))) { while (l < size) { push(l); l = (2 * l); if (g(op(sm, d[l]))) { sm = op(sm, d[l]); l++; } } return l - size; } sm = op(sm, d[l]); l++; } while ((l & -l) != l); return _n; } template <bool (*g)(S)> int min_left(int r) { return min_left(r, [](S x) { return g(x); }); } template <class G> int min_left(int r, G g) { assert(0 <= r && r <= _n); assert(g(e())); if (r == 0) return 0; r += size; for (int i = log; i >= 1; i--) push((r - 1) >> i); S sm = e(); do { r--; while (r > 1 && (r % 2)) r >>= 1; if (!g(op(d[r], sm))) { while (r < size) { push(r); r = (2 * r + 1); if (g(op(d[r], sm))) { sm = op(d[r], sm); r--; } } return r + 1 - size; } sm = op(d[r], sm); } while ((r & -r) != r); return 0; } private: int _n, size, log; std::vector<S> d; std::vector<F> lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; } // namespace atcoder using namespace std; using namespace atcoder; using ll = long long; using P = pair<int, int>; using VI = vector<int>; using VVI = vector<VI>; struct HLD { std::vector<std::vector<int>>& to; int root, n; std::vector<int> sz, parent, depth, idx, ridx, head; HLD(std::vector<std::vector<int>>& to, int root = 0) : to(to), root(root), n(to.size()), sz(n), parent(n), depth(n), idx(n), ridx(n), head(n) { init_tree_data(root); int x = 0; assign_idx(root, root, x); } void init_tree_data(int u, int p = -1, int d = 0) { parent[u] = p; depth[u] = d; int s = 1; for (int v : to[u]) { if (v == p) continue; init_tree_data(v, u, d + 1); s += sz[v]; } sz[u] = s; } void assign_idx(int u, int h, int& nxt, int p = -1) { head[u] = h; idx[u] = nxt++; if (sz[u] == 1) { ridx[u] = nxt; return; } int mxsize = 0; int mi; for (int v : to[u]) { if (v == p) continue; if (sz[v] > mxsize) { mxsize = sz[v]; mi = v; } } assign_idx(mi, h, nxt, u); for (int v : to[u]) { if (v == p || v == mi) continue; assign_idx(v, v, nxt, u); } ridx[u] = nxt; } }; struct S { int even, odd; }; S op(S x, S y) { return {max(x.even, y.even), max(x.odd, y.odd)}; } S e() { return {-1, -1}; } S mapping(bool f, S x) { if (f) return {x.odd, x.even}; else return x; } bool composition(bool f, bool g) { return f ^ g; } bool id() { return false; } struct E { int u, v, state; }; VVI to; P dfs(int u, int p = -1, int depth = 0) { P ret = {u, depth}; for (int v : to[u]) { if (v == p) continue; P r = dfs(v, u, depth + 1); if (r.second > ret.second) ret = r; } return ret; } int main() { int n; cin >> n; to.resize(n); vector<E> es(n - 1); for (int i = 0; i < (n - 1); ++i) { int u, v, t; cin >> u >> v >> t; --u, --v; es[i] = {u, v, t}; to[u].push_back(v); to[v].push_back(u); } int m; cin >> m; VI query(m); for (int i = 0; i < (m); ++i) { cin >> query[i]; query[i]--; } VI ab(2); ab[0] = dfs(0).first; ab[1] = dfs(ab[0]).first; VVI ans(2, VI(m)); for (int tt = 0; tt < (2); ++tt) { int a = ab[tt]; HLD hld(to, a); VI is_odd(n); for (int i = 0; i < (n - 1); ++i) { int u = es[i].u, v = es[i].v, s = es[i].state; if (hld.parent[u] == v) { swap(u, v); swap(es[i].u, es[i].v); } is_odd[v] = s; } queue<int> que; que.push(a); while (!que.empty()) { int u = que.front(); que.pop(); for (int v : to[u]) { if (v == hld.parent[u]) continue; is_odd[v] ^= is_odd[u]; que.push(v); } } vector<S> init_vec(n); for (int i = 0; i < (n); ++i) { if (is_odd[i]) { init_vec[hld.idx[i]] = {-1, hld.depth[i]}; } else { init_vec[hld.idx[i]] = {hld.depth[i], -1}; } } lazy_segtree<S, op, e, bool, mapping, composition, id> seg(init_vec); for (int i = 0; i < (m); ++i) { int ei = query[i]; int v = es[ei].v; int vin = hld.idx[v], vout = hld.ridx[v]; seg.apply(vin, vout, true); ans[tt][i] = seg.all_prod().even; } } for (int i = 0; i < (m); ++i) cout << max(ans[0][i], ans[1][i]) << '\n'; }
#include <bits/stdc++.h> using namespace std; inline int readint() { int x = 0, f = 1; char ch = getchar(); while (ch < '0' || ch > '9') { if (ch == '-') f = -1; ch = getchar(); } while (ch >= '0' && ch <= '9') { x = (x << 1) + (x << 3) + (ch ^ 48); ch = getchar(); } return x * f; } int _tmp[20]; int _tn; inline void printint(int x) { int f = 1; if (x == 0) { puts("0"); return; } if (x < 0) { f = -1; x = -x; } _tn = 0; while (x) { _tmp[++_tn] = x % 10; x /= 10; } if (f == -1) putchar('-'); for (int i = _tn; i >= 1; i--) putchar('0' + _tmp[i]); puts(""); } inline void chmax(int &x, int y) { x = max(x, y); } const int N = 5e5 + 5; const int INF = 123456789; int n, m, t = 1, q; int X[N], Y[N], Z[N], p[N], B[N], E[N], d[N], poi[N * 2]; vector<int> nei[N]; void dfs(int x) { B[x] = E[x] = ++m; poi[m] = x; for (int i = 0; i < int(nei[x].size()); i++) { int to = nei[x][i]; if (to != p[x]) { p[to] = x; d[to] = d[x] + 1; dfs(to); E[x] = ++m; poi[m] = x; } } } int lson[N * 4]; int rson[N * 4]; int val1[2][N * 4]; int val2[N * 4]; int val3[2][N * 4]; int val4[2][N * 4]; int val5[2][N * 4]; int tag[N * 4]; void update(int pos) { for (int i = 0; i < 2; i++) { val1[i][pos] = max(val1[i][lson[pos]], val1[i][rson[pos]]); val3[i][pos] = max(val3[i][lson[pos]], val3[i][rson[pos]]); val4[i][pos] = max(val4[i][lson[pos]], val4[i][rson[pos]]); val5[i][pos] = max(val5[i][lson[pos]], val5[i][rson[pos]]); } val2[pos] = max(val2[lson[pos]], val2[rson[pos]]); for (int i = 0; i < 2; i++) { if (val1[i][lson[pos]] != -INF && val2[rson[pos]] != -INF) chmax(val3[i][pos], val1[i][lson[pos]] + val2[rson[pos]]); if (val2[lson[pos]] != -INF && val1[i][rson[pos]] != -INF) chmax(val4[i][pos], val2[lson[pos]] + val1[i][rson[pos]]); } for (int i = 0; i < 2; i++) for (int j = 0; j < 2; j++) { if (val1[i][lson[pos]] != -INF && val4[i][rson[pos]] != -INF) chmax(val5[i ^ j][pos], val1[i][lson[pos]] + val4[i][rson[pos]]); if (val3[i][lson[pos]] != -INF && val1[i][rson[pos]] != -INF) chmax(val5[i ^ j][pos], val3[i][lson[pos]] + val1[i][rson[pos]]); } } void flip(int pos) { tag[pos] ^= 1; swap(val1[0][pos], val1[1][pos]); swap(val3[0][pos], val3[1][pos]); swap(val4[0][pos], val4[1][pos]); } void pushdown(int pos) { if (tag[pos]) { flip(lson[pos]); flip(rson[pos]); tag[pos] = 0; } } void build(int pos, int x, int y) { for (int i = 0; i < 2; i++) val1[i][pos] = val3[i][pos] = val4[i][pos] = val5[i][pos] = -INF; val2[pos] = -INF; if (x == y) { val1[0][pos] = d[poi[x]]; val2[pos] = -2 * d[poi[x]]; val3[0][pos] = val4[0][pos] = -d[poi[x]]; val5[0][pos] = 0; return; } int mid = (x + y) >> 1; lson[pos] = ++t; rson[pos] = ++t; build(lson[pos], x, mid); build(rson[pos], mid + 1, y); update(pos); } void modify(int pos, int x, int y, int l, int r) { if (x >= l && y <= r) { flip(pos); return; } if (x > r || y < l) return; pushdown(pos); int mid = (x + y) >> 1; modify(lson[pos], x, mid, l, r); modify(rson[pos], mid + 1, y, l, r); update(pos); } int main() { n = readint(); for (int i = 1; i < n; i++) { X[i] = readint(); Y[i] = readint(); Z[i] = readint(); nei[X[i]].push_back(Y[i]); nei[Y[i]].push_back(X[i]); } p[1] = 1; dfs(1); build(1, 1, m); for (int i = 1; i < n; i++) if (Z[i]) { int x = X[i], y = Y[i]; if (p[y] == x) swap(x, y); modify(1, 1, m, B[x], E[x]); } q = readint(); for (int i = 1; i <= q; i++) { int id; id = readint(); int x = X[id], y = Y[id]; if (p[y] == x) swap(x, y); modify(1, 1, m, B[x], E[x]); printint(val5[0][1]); } return 0; }
#include <bits/stdc++.h> using namespace std; int nxt[1000010 << 1], to[1000010 << 1], head[1000010], cnt = 1; int w[1000010 << 1]; void add(int u, int v, int w1) { nxt[++cnt] = head[u]; to[cnt] = v; w[cnt] = w1; head[u] = cnt; } int id[1000010], lid[1000010], rid[1000010], idx; int dep[1000010], pos[1000010], wd[1000010]; namespace segment { int val[1000010 << 2][2], maxn[1000010 << 2], vl[1000010 << 2][2], vr[1000010 << 2][2], ml[1000010 << 2][2], tag[1000010 << 2]; void update(int u) { maxn[u] = max(maxn[u << 1], maxn[u << 1 | 1]); for (int _ = 0; _ <= 1; _++) val[u][_] = max(val[u << 1][_], val[u << 1 | 1][_]), vl[u][_] = max(vl[u << 1][_], vl[u << 1 | 1][_]), vr[u][_] = max(vr[u << 1][_], vr[u << 1 | 1][_]), ml[u][_] = max(ml[u << 1][_], ml[u << 1 | 1][_]), vl[u][_] = max(vl[u][_], val[u << 1][_] + maxn[u << 1 | 1]), vr[u][_] = max(vr[u][_], maxn[u << 1] + val[u << 1 | 1][_]); for (int l = 0; l <= 1; l++) for (int r = 0; r <= 1; r++) ml[u][l ^ r] = max(ml[u][l ^ r], max(vl[u << 1][l] + val[u << 1 | 1][r], val[u << 1][l] + vr[u << 1 | 1][r])); } void set_tag(int u) { swap(val[u][0], val[u][1]), swap(vl[u][0], vl[u][1]), swap(vr[u][0], vr[u][1]); tag[u] ^= 1; } void push_down(int u) { if (!tag[u]) return; set_tag(u << 1), set_tag(u << 1 | 1); tag[u] = 0; } void build(int u, int l, int r) { if (l == r) { int x = id[l], i = wd[x] & 1; val[u][i] = dep[x], maxn[u] = -2 * dep[x]; vl[u][i] = vr[u][i] = -dep[x]; return; } int mid = (l + r) >> 1; build(u << 1, l, mid), build(u << 1 | 1, mid + 1, r); update(u); } void insert(int u, int l, int r, int L, int R) { if (L <= l && r <= R) { set_tag(u); return; } int mid = (l + r) >> 1; push_down(u); if (L <= mid) insert(u << 1, l, mid, L, R); if (R > mid) insert(u << 1 | 1, mid + 1, r, L, R); update(u); } } // namespace segment void dfs(int u, int p) { dep[u] = dep[p] + 1; id[lid[u] = ++idx] = u; for (int i = head[u]; i; i = nxt[i]) { int v = to[i]; if (v == p) continue; pos[i >> 1] = v; wd[v] = wd[u] + w[i]; dfs(v, u); id[++idx] = u; } rid[u] = idx; } int main() { memset(segment::val, 0xcf, sizeof(segment::val)); memset(segment::vl, 0xcf, sizeof(segment::vl)); memset(segment::vr, 0xcf, sizeof(segment::vr)); int n; scanf("%d", &n); for (int i = 1; i < n; i++) { int u, v, w; scanf("%d%d%d", &u, &v, &w); add(u, v, w), add(v, u, w); } dep[0] = -1; dfs(1, 0); segment::build(1, 1, idx); int m; scanf("%d", &m); for (int i = 1; i <= m; i++) { int x; scanf("%d", &x); segment::insert(1, 1, idx, lid[pos[x]], rid[pos[x]]); printf("%d\n", segment::ml[1][0]); } return 0; }
#include <bits/stdc++.h> using namespace std; template <typename T1, typename T2> istream &operator>>(istream &in, pair<T1, T2> &a) { in >> a.first >> a.second; return in; } template <typename T1, typename T2> ostream &operator<<(ostream &out, pair<T1, T2> a) { out << a.first << " " << a.second; return out; } template <typename T, typename T1> T amax(T &a, T1 b) { if (b > a) a = b; return a; } template <typename T, typename T1> T amin(T &a, T1 b) { if (b < a) a = b; return a; } const long long INF = 1e18; const int32_t M = 1e9 + 7; const int32_t MM = 998244353; const long long N = 5e5 + 5; const int32_t maxn = N; template <typename NODE, typename UPDATE> struct segtree { bool built = false, lazy[4 * maxn]; NODE zero = NODE(), t[4 * maxn]; UPDATE noop = UPDATE(), upds[4 * maxn]; int32_t tl[4 * maxn], tr[4 * maxn]; inline void pushdown(int32_t v) { if (lazy[v]) { apply(v * 2, upds[v]); apply(v * 2 + 1, upds[v]); lazy[v] = 0; upds[v] = noop; } } inline void apply(int32_t v, UPDATE &val) { if (tl[v] != tr[v]) { lazy[v] = 1; upds[v].combine(val, tl[v], tr[v]); } val.apply(t[v], tl[v], tr[v]); } template <typename T> void build(T a, int32_t v, int32_t l, int32_t r) { tl[v] = l; tr[v] = r; if (l == r) { t[v] = a[l]; return; } else { int32_t tm = (l + r) / 2; build(a, v * 2, l, tm); build(a, v * 2 + 1, tm + 1, r); t[v].merge(t[v * 2], t[v * 2 + 1]); } } NODE query(int32_t v, long long l, long long r) { if (l > tr[v] || r < tl[v]) return zero; if (l <= tl[v] && tr[v] <= r) { return t[v]; } pushdown(v); NODE a, b, ans; a = query(v * 2, l, r); b = query(v * 2 + 1, l, r); ans.merge(a, b); return ans; } void rupd(int32_t v, long long l, long long r, UPDATE &val) { if (l > tr[v] || r < tl[v]) return; if (l <= tl[v] && tr[v] <= r) { apply(v, val); return; } pushdown(v); rupd(v * 2, l, r, val); rupd(v * 2 + 1, l, r, val); t[v].merge(t[v * 2], t[v * 2 + 1]); } template <typename T> long long descent_right(long long l, T x, int32_t v, NODE &prev) { if (l > tr[v]) return len; if (l <= tl[v]) { NODE cur; cur.merge(prev, t[v]); if (!cur.check(x)) { swap(prev, cur); return len; } if (tl[v] == tr[v]) { return tr[v]; } } pushdown(v); long long ans = descent_right(l, x, v * 2, prev); if (ans != len) return ans; return descent_right(l, x, v * 2 + 1, prev); } template <typename T> long long descent_left(long long r, T x, int32_t v, NODE &prev) { if (r < tl[v]) return -1; if (r >= tr[v]) { NODE cur; cur.merge(t[v], prev); if (!cur.check(x)) { swap(cur, prev); return -1; } if (tl[v] == tr[v]) { return tl[v]; } } pushdown(v); long long ans = descent_left(r, x, v * 2 + 1, prev); if (ans != -1) return ans; return descent_left(r, x, v * 2, prev); } long long len = maxn; void clear() { fill(t, t + 4 * len, zero); fill(lazy, lazy + 4 * len, false); fill(upds, upds + 4 * len, noop); } template <typename T> void build(T a) { build(a, 1, 0, len - 1); built = true; } template <typename T> long long descent_right(long long l, T x) { NODE prev = zero; return descent_right(l, x, 1, prev); } template <typename T> long long descent_left(long long r, T x) { NODE prev = zero; return descent_left(r, x, 1, prev); } NODE query(long long l, long long r) { if (!built) build(t); return query(1, l, r); } void rupd(long long l, long long r, UPDATE val) { if (!built) build(t); rupd(1, l, r, val); } }; struct node1 { long long e = 0, o = 0; node1() {} node1(long long val) { e = val; } void merge(node1 &l, node1 &r) { e = max(l.e, r.e); o = max(l.o, r.o); } bool check(long long x) { return false; } }; struct update1 { long long v = 0; update1() {} update1(long long val) { v = val; } void combine(update1 &other, int32_t tl, int32_t tr) { v ^= other.v; } void apply(node1 &x, int32_t tl, int32_t tr) { if (v) { swap(x.e, x.o); } } }; segtree<node1, update1> t; long long n, m; pair<long long, long long> edgs[N]; vector<long long> f, q; long long tim; long long st[N], et[N], dep[N], ev[N]; vector<pair<long long, long long> > v[N]; void dfs(long long z, long long p = 0, long long d = 0) { st[z] = tim++; dep[st[z]] = d; for (pair<long long, long long> x : v[z]) { if (x.first == p) continue; ev[x.second] = x.first; dfs(x.first, z, d + 1); } et[z] = tim - 1; } pair<long long, long long> auxdfs(long long z, long long p = 0, long long d = 0) { pair<long long, long long> ret = {d, z}; for (pair<long long, long long> x : v[z]) { if (x.first == p) continue; pair<long long, long long> tmp = auxdfs(x.first, z, d + 1); amax(ret, tmp); } return ret; } long long ans[N]; void solve() { cin >> n; for (long long i = 1; i < n; i++) { long long x, y, z; cin >> x >> y >> z; edgs[i] = {x, y}; v[x].push_back({y, i}); v[y].push_back({x, i}); if (z) f.push_back(i); } cin >> m; for (long long i = 0; i < m; i++) { long long x; cin >> x; q.push_back(x); } long long root = 1; for (long long zz = 0; zz < 2; zz++) { root = auxdfs(root).second; tim = 0; dfs(root); t.clear(); t.build(dep); for (long long x : f) { long long y = ev[x]; t.rupd(st[y], et[y], 1); } for (long long i = 0; i < m; i++) { long long x = q[i]; long long y = ev[x]; t.rupd(st[y], et[y], 1); amax(ans[i], t.query(st[root], et[root]).e); } } for (long long i = 0; i < m; i++) { cout << ans[i] << "\n"; } } signed main() { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); long long t = 1; while (t--) solve(); return 0; }
#include <bits/stdc++.h> #pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") using namespace std; namespace io { const int BUFSIZE = 1 << 20; char ibuf[BUFSIZE + 1], *is = ibuf, *it = ibuf; char obuf[BUFSIZE + 1], *os = obuf, *ot = obuf + BUFSIZE; inline char read_char() { if (is == it) { it = (is = ibuf) + fread(ibuf, 1, BUFSIZE, stdin); if (is == it) *it++ = EOF; } return *is++; } template <class T> inline void read_int(T &x) { T f = 1; char c = read_char(); while (!isdigit(c)) { if (c == '-') f = -1; c = read_char(); } x = 0; while (isdigit(c)) { x = x * 10 + c - '0'; c = read_char(); } x *= f; } inline void read_str(char *s) { char c = read_char(); while (c <= ' ') { c = read_char(); } while (c > ' ') { *s++ = c; c = read_char(); } *s = 0; } inline void flush() { fwrite(obuf, 1, os - obuf, stdout); os = obuf; } inline void print_char(char c) { *os++ = c; if (os == ot) { flush(); } } template <class T> inline void print_int(T x, char c = 0) { static char q[40]; if (!x) { print_char('0'); } else { if (x < 0) { print_char('-'); x = -x; } int top = 0; while (x) { q[top++] = x % 10 + '0'; x /= 10; } while (top--) { print_char(q[top]); } } if (c) print_char(c); } inline void print_str(char *s, char c = 0) { while (*s) { print_char(*s++); } if (c) print_char(c); } struct flusher_t { inline ~flusher_t() { flush(); } } flusher; } // namespace io using io::print_char; using io::print_int; using io::print_str; using io::read_char; using io::read_int; using io::read_str; const int N = 500005; int n, Q, tot, dfn[N], dl[N], pp[N], dr[N], dfc, st[20][N * 2], lg2[N * 2], dep[N], dist[N]; vector<pair<int, int> > G[N]; inline int LCA(int l, int r) { l = dfn[l], r = dfn[r]; if (l > r) swap(l, r); int i = lg2[r - l + 1]; if (dep[st[i][l]] < dep[st[i][r - (1 << i) + 1]]) return st[i][l]; else return st[i][r - (1 << i) + 1]; } inline int getdist(int u, int v) { return dep[u] + dep[v] - 2 * dep[LCA(u, v)]; } struct Node { int u, v, d; }; inline Node Merge(const Node &a, const Node &b) { if (a.d == -1) return b; if (b.d == -1) return a; Node ret; if (a.d > b.d) { ret = a; } else { ret = b; } int d1 = getdist(a.u, b.u), d2 = getdist(a.u, b.v), d3 = getdist(a.v, b.u), d4 = getdist(a.v, b.v); int md = max(max(d1, d2), max(d3, d4)); if (md <= ret.d) return ret; ret.d = md; if (d1 == md) { ret.u = a.u; ret.v = b.u; } else if (d2 == md) { ret.u = a.u; ret.v = b.v; } else if (d3 == md) { ret.u = a.v; ret.v = b.u; } else { ret.u = a.v; ret.v = b.v; } return ret; } Node tr[N * 4][2]; int tag[N * 4]; void build(int i, int l, int r) { tag[i] = 0; if (l == r) { int u = pp[l]; tr[i][dist[u]].u = tr[i][dist[u]].v = u; tr[i][dist[u]].d = 0; tr[i][dist[u] ^ 1].u = tr[i][dist[u] ^ 1].v = 0; tr[i][dist[u] ^ 1].d = -1; return; } int mid = (l + r) >> 1; build(i << 1, l, mid); build(i << 1 | 1, mid + 1, r); tr[i][0] = Merge(tr[i << 1][0], tr[i << 1 | 1][0]); tr[i][1] = Merge(tr[i << 1][1], tr[i << 1 | 1][1]); } inline void pushdown(int i) { if (tag[i]) { swap(tr[i << 1][0], tr[i << 1][1]); swap(tr[i << 1 | 1][0], tr[i << 1 | 1][1]); tag[i << 1] ^= 1; tag[i << 1 | 1] ^= 1; tag[i] = 0; } } void modify(int i, int l, int r, int lf, int rg) { if (lf <= l && r <= rg) { swap(tr[i][0], tr[i][1]); tag[i] ^= 1; return; } pushdown(i); int mid = (l + r) >> 1; if (lf <= mid) modify(i << 1, l, mid, lf, rg); if (rg > mid) modify(i << 1 | 1, mid + 1, r, lf, rg); tr[i][0] = Merge(tr[i << 1][0], tr[i << 1 | 1][0]); tr[i][1] = Merge(tr[i << 1][1], tr[i << 1 | 1][1]); } void dfs(int u, int lst, int depth, int D) { dl[u] = ++dfc; pp[dfc] = u; st[0][dfn[u] = ++tot] = u; dep[u] = depth; dist[u] = D; for (auto &e : G[u]) { int v = e.first; if (v == lst) continue; dfs(v, u, depth + 1, D ^ e.second); st[0][++tot] = u; } dr[u] = dfc; } int eu[N], ev[N]; int main() { read_int(n); for (int i = 1; i < n; i++) { int u, v, w; read_int(u); eu[i] = u; read_int(v); ev[i] = v; read_int(w); G[u].push_back(make_pair(v, w)); G[v].push_back(make_pair(u, w)); } tot = 0; dfs(1, 0, 0, 0); lg2[0] = -1; for (int i = 1; i <= tot; i++) lg2[i] = lg2[i - 1] + ((i & (i - 1)) ? 0 : 1); for (int i = 1; i < 20; i++) { for (int j = 1; j <= tot - (1 << i) + 1; j++) { if (dep[st[i - 1][j]] < dep[st[i - 1][j + (1 << (i - 1))]]) st[i][j] = st[i - 1][j]; else st[i][j] = st[i - 1][j + (1 << (i - 1))]; } } build(1, 1, n); read_int(Q); for (int i = 1; i < n; i++) { if (dl[eu[i]] > dl[ev[i]]) swap(eu[i], ev[i]); } while (Q--) { int eid; read_int(eid); modify(1, 1, n, dl[ev[eid]], dr[ev[eid]]); print_int(max(tr[1][0].d, tr[1][1].d), '\n'); } return 0; }
#include <bits/stdc++.h> #pragma GCC optimize("O3") using namespace std; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); template <class T> inline bool setmin(T &a, T b) { if (a > b) return a = b, 1; return 0; } template <class T> inline bool setmax(T &a, T b) { if (a < b) return a = b, 1; return 0; } template <class T> inline T fast(T a, T b, T mod) { long long res = 1; while (b) { if (b & 1) res = (res * a) % mod; a = (a * a) % mod; b >>= 1; } return res; } template <class T> istream &operator>>(istream &os, vector<T> &container) { for (auto &u : container) os >> u; return os; } template <class T> ostream &operator<<(ostream &os, const vector<T> &container) { for (auto &u : container) os << u << " "; return os; } template <class T> inline T gcd(T a, T b) { while (b) swap(a %= b, b); return abs(a); } const long long INF = 1e9 + 7; const long long mod = 998244353; const long long BIG_INF = 1e18 + 7; const long long N = 1e6 + 7; const long long T = 1 << 20; const long double inf = 1e18; const long double eps = 1e-14; long long n, m, k; vector<vector<pair<int, int> > > G(N); int najd = 1, dist, cnt_pre; vector<int> preorder(N), glebokosc(N), rev_pre(N), kolor(N); vector<pair<int, int> > przedzial_na_drzewie(N); struct Tree { vector<int> merge(vector<int> &a, vector<int> &b) { return {max(a[0], b[0]), max(a[1], b[1])}; } vector<vector<int> > tree; vector<int> lazy; Tree() { tree = vector<vector<int> >(T * 2, vector<int>(2, -1)); lazy = vector<int>(T * 2, false); for (int i = 1; i <= cnt_pre; i++) tree[i + T][kolor[rev_pre[i]]] = glebokosc[rev_pre[i]]; for (int i = T - 1; i >= 0; i--) tree[i] = merge(tree[i * 2], tree[i * 2 + 1]); }; void push(int v) { if (lazy[v]) { swap(tree[v][0], tree[v][1]); if (v < T) { lazy[v * 2] ^= 1; lazy[v * 2 + 1] ^= 1; } lazy[v] = 0; } } void flip(int a, int b, int u = 1, int lo = 0, int hi = T - 1) { push(u); if (hi < a or b < lo) return; if (a <= lo and hi <= b) { lazy[u] ^= 1; push(u); return; } int mid = (lo + hi) / 2; flip(a, b, u * 2, lo, mid); flip(a, b, u * 2 + 1, mid + 1, hi); tree[u] = merge(tree[u * 2], tree[u * 2 + 1]); } void flip(pair<int, int> kraw) { int v = (glebokosc[kraw.first] < glebokosc[kraw.second] ? kraw.second : kraw.first); flip(przedzial_na_drzewie[v].first, przedzial_na_drzewie[v].second); } int ask() { return tree[1][0]; } }; void dfs2(int second, int p = -1, int gl = 0, int kol = 0) { if (p == -1) cnt_pre = 0; preorder[second] = ++cnt_pre; rev_pre[cnt_pre] = second; glebokosc[second] = gl; kolor[second] = kol; for (auto &u : G[second]) if (u.first != p) dfs2(u.first, second, gl + 1, kol ^ u.second); przedzial_na_drzewie[second] = {preorder[second], cnt_pre}; } vector<int> solve(vector<pair<int, int> > &kraw, vector<int> zap, int root) { dfs2(root); Tree tree; vector<int> ret; for (auto &u : zap) { tree.flip(kraw[u]); ret.push_back(tree.ask()); } return ret; } void dfs(int second = najd, int gl = 0, int przodek = -1) { if (gl == 0) dist = -1; if (gl > dist) { dist = gl; najd = second; } for (auto &u : G[second]) if (u.first != przodek) dfs(u.first, gl + 1, second); } void solve() { cin >> n; vector<pair<int, int> > kraw(n, {-1, -1}); for (int i = 1; i < n; i++) { int a, b, c; cin >> a >> b >> c; G[a].push_back({b, c}); G[b].push_back({a, c}); kraw[i] = {a, b}; } vector<int> konce; dfs(); konce.push_back(najd); dfs(); konce.push_back(najd); cin >> m; vector<int> zapytania(m); cin >> zapytania; vector<int> A = solve(kraw, zapytania, konce[0]); vector<int> B = solve(kraw, zapytania, konce[1]); for (int i = 0; i < m; i++) cout << max(A[i], B[i]) << '\n'; } signed main() { ios::sync_with_stdio(0); cin.tie(0); int t = 1; while (t--) solve(); }
#include <bits/stdc++.h> using ll = long long; using ld = long double; using namespace std; const int T = 1 << 20; const int N = 5e5 + 500; int n, q, a, b, c; pair<int, int> e[N]; vector<pair<int, int>> G[N]; pair<int, int> farest(int v = 1, int p = 0) { pair<int, int> mx = {0, v}; for (auto [u, w] : G[v]) if (u != p) { auto cur = farest(u, v); cur.first++; mx = max(mx, cur); } return mx; } struct tree { struct node { int x, y, flag; } s[T + T]; node combine(node a, node b) { return {max(a.x, b.x), max(a.y, b.y)}; } void change(int v) { s[v].flag ^= 1; swap(s[v].x, s[v].y); } void push(int v) { if (!s[v].flag) return; for (auto u : {2 * v, 2 * v + 1}) change(u); s[v].flag = 0; } void modify(int x, int y, int v = 1, int l = 1, int r = n) { if (y < l || r < x) return; if (x <= l && r <= y) { change(v); return; } push(v); int m = l + r >> 1; modify(x, y, 2 * v, l, m); modify(x, y, 2 * v + 1, m + 1, r); s[v] = combine(s[2 * v], s[2 * v + 1]); } int par[N], dis[N], time, in[N], out[N], ord[N]; void dfs(int v, int p = -1) { in[v] = ++time; ord[time] = v; for (auto [u, w] : G[v]) { if (u != p) { dis[u] = dis[v] + 1; par[u] = par[v] ^ w; dfs(u, v); } } out[v] = time; } void build(int v = 1, int l = 1, int r = n) { if (l == r) { int u = ord[l]; if (par[u] % 2 == 0) s[v].x = dis[u]; else s[v].y = dis[u]; return; } int m = l + r >> 1; build(2 * v, l, m); build(2 * v + 1, m + 1, r); s[v] = combine(s[2 * v], s[2 * v + 1]); } void flip(int u, int v) { if (dis[u] > dis[v]) swap(u, v); modify(in[v], out[v]); } } D[2]; int main() { scanf("%d", &n); for (int i = 1; i <= n - 1; ++i) { scanf("%d%d%d", &a, &b, &c); e[i] = {a, b}; G[a].push_back({b, c}); G[b].push_back({a, c}); } int x = farest().second; int y = farest(x).second; D[0].dfs(x); D[1].dfs(y); D[0].build(); D[1].build(); scanf("%d", &q); while (q--) { scanf("%d", &a); for (int i = 0; i <= 1; ++i) D[i].flip(e[a].first, e[a].second); printf("%d\n", max(D[0].s[1].x, D[1].s[1].x)); } return 0; }
#include <bits/stdc++.h> using ll = long long; using ld = long double; using namespace std; const int T = 1 << 20; const int N = 5e5 + 500; int n, q, a, b, c; pair<int, int> e[N]; vector<pair<int, int>> G[N]; pair<int, int> farest(int v = 0, int p = -1) { pair<int, int> mx = {0, v}; for (auto [u, w] : G[v]) if (u != p) { auto cur = farest(u, v); cur.first++; mx = max(mx, cur); } return mx; } struct tree { struct node { int x, y, flag; } s[T + T]; node combine(node a, node b) { return {max(a.x, b.x), max(a.y, b.y)}; } void change(int v) { s[v].flag ^= 1; swap(s[v].x, s[v].y); } void push(int v) { if (!s[v].flag) return; for (auto u : {2 * v, 2 * v + 1}) change(u); s[v].flag = 0; } void modify(int x, int y, int v = 1, int l = 0, int r = n - 1) { if (y < l || r < x) return; if (x <= l && r <= y) { change(v); return; } push(v); int m = l + r >> 1; modify(x, y, 2 * v, l, m); modify(x, y, 2 * v + 1, m + 1, r); s[v] = combine(s[2 * v], s[2 * v + 1]); } int par[N], dis[N], time = -1, in[N], out[N], ord[N]; void dfs(int v, int p = -1) { in[v] = ++time; ord[time] = v; for (auto [u, w] : G[v]) { if (u != p) { dis[u] = dis[v] + 1; par[u] = par[v] ^ w; dfs(u, v); } } out[v] = time; } void build(int v = 1, int l = 0, int r = n - 1) { if (l == r) { int u = ord[l]; if (par[u] % 2 == 0) s[v].x = dis[u]; else s[v].y = dis[u]; return; } int m = l + r >> 1; build(2 * v, l, m); build(2 * v + 1, m + 1, r); s[v] = combine(s[2 * v], s[2 * v + 1]); } void flip(int u, int v) { if (dis[u] > dis[v]) swap(u, v); modify(in[v], out[v]); } } D[2]; int main() { scanf("%d", &n); for (int i = 1; i <= n - 1; ++i) { scanf("%d%d%d", &a, &b, &c); a--; b--; e[i] = {a, b}; G[a].push_back({b, c}); G[b].push_back({a, c}); } int x = farest().second; int y = farest(x).second; D[0].dfs(x); D[1].dfs(y); D[0].build(); D[1].build(); scanf("%d", &q); while (q--) { scanf("%d", &a); for (int i = 0; i <= 1; ++i) D[i].flip(e[a].first, e[a].second); printf("%d\n", max(D[0].s[1].x, D[1].s[1].x)); } return 0; }
#include <bits/stdc++.h> using namespace std; const int MN = 5e5 + 5; struct node { int val[2]; } T[MN << 2]; node operator+(node a, node b) { return (node){max(a.val[0], b.val[0]), max(a.val[1], b.val[1])}; } int N, M, idx[MN], ans[MN], fa[MN], dep[MN], rt; vector<pair<int, int> > a[MN]; vector<pair<int, int> > G; inline void chkmax(int &x, int y) { x = max(x, y); } struct sol { int f[MN], l[MN], siz, r[MN], rev[MN], tg[MN << 2], dep[MN], fa[MN]; inline void dfs(int x) { rev[l[x] = ++siz] = x; for (auto o : a[x]) { if (o.first == fa[x]) continue; int y = o.first; fa[y] = x, dep[y] = dep[x] + 1; f[y] = (f[x] + o.second) & 1; dfs(y); } r[x] = siz; } inline void build(int idx, int l, int r) { tg[idx] = 0; if (l == r) { T[idx].val[f[rev[l]]] = dep[rev[l]]; T[idx].val[f[rev[l]] ^ 1] = 0; return; } int mid = l + r >> 1; build(idx << 1, l, mid), build(idx << 1 | 1, mid + 1, r); T[idx] = T[idx << 1] + T[idx << 1 | 1]; } inline void R(int o) { swap(T[o].val[0], T[o].val[1]); tg[o] ^= 1; } inline void pushdown(int o) { if (tg[o]) R(o << 1), R(o << 1 | 1), tg[o] = 0; } inline void modify(int now, int l, int r, int ql, int qr) { if (l == ql && r == qr) return R(now); int mid = l + r >> 1; pushdown(now); if (mid >= qr) modify(now << 1, l, mid, ql, qr); else if (mid + 1 <= ql) modify(now << 1 | 1, mid + 1, r, ql, qr); else modify(now << 1, l, mid, ql, mid), modify(now << 1 | 1, mid + 1, r, mid + 1, qr); T[now] = T[now << 1] + T[now << 1 | 1]; } inline void run(int rt) { fa[rt] = dep[rt] = siz = 0; dfs(rt); build(1, 1, N); for (int i = 1; i <= M; ++i) { int x = G[idx[i] - 1].first, y = G[idx[i] - 1].second; if (fa[x] == y) swap(x, y); modify(1, 1, N, l[y], r[y]); chkmax(ans[i], T[1].val[0]); } } } A, B; inline void dfs(int x) { for (auto o : a[x]) { if (o.first == fa[x]) continue; int y = o.first; fa[y] = x, dep[y] = dep[x] + 1; dfs(y); } if (!rt || dep[x] > dep[rt]) rt = x; } int main() { scanf("%d", &N); for (int i = 1; i < N; ++i) { int u, v, w; scanf("%d%d%d", &u, &v, &w); a[u].emplace_back(make_pair(v, w)); a[v].emplace_back(make_pair(u, w)); G.emplace_back(make_pair(u, v)); } scanf("%d", &M); for (int i = 1; i <= M; ++i) scanf("%d", &idx[i]); rt = 0, fa[1] = dep[1] = 0; dfs(1); int r1 = rt, r2; rt = 0; fa[r1] = dep[r1] = 0; dfs(r1); r2 = rt; A.run(r1); B.run(r2); for (int i = 1; i <= M; ++i) printf("%d\n", ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 500000; int s[N], t[N], type[N]; int q, qind[N]; void dfs(int n, vector<vector<int>>& adj, int root, void preVisit(int, int) = 0, void postVisit(int, int) = 0, void traverseTreeEdge(int, int, int) = 0, void traverseBackEdge(int, int) = 0) { vector<int> parent(n, -2); vector<int> stackNode(n); vector<int> stackEdgeIndex(n); int stackSize = 1; stackNode[0] = root; stackEdgeIndex[0] = 0; parent[root] = -1; while (stackSize > 0) { int node = stackNode[stackSize - 1]; int edgeIndex = stackEdgeIndex[stackSize - 1]; if (edgeIndex == 0 && preVisit) { preVisit(node, parent[node]); } if (edgeIndex == adj[node].size()) { stackSize--; if (postVisit) { postVisit(node, parent[node]); } } else { int e = adj[node][edgeIndex]; int other = s[e] == node ? t[e] : s[e]; stackEdgeIndex[stackSize - 1]++; if (parent[other] == -2) { parent[other] = node; if (traverseTreeEdge) traverseTreeEdge(node, other, e); stackNode[stackSize] = other; stackEdgeIndex[stackSize] = 0; stackSize++; } else if (other != parent[node]) { if (traverseBackEdge) traverseBackEdge(node, other); } } } } int depth[N]; bool good[N]; int preorder[N], postorder[N]; int subtreeRoot[N]; int curorder; void preVisit(int v, int p) { preorder[v] = curorder++; if (p == -1) { depth[v] = 0; good[v] = true; } else { depth[v] = depth[p] + 1; } } void postVisit(int v, int p) { postorder[v] = curorder - 1; } void traverseTreeEdge(int p, int v, int e) { if (type[e]) good[v] = !good[p]; else good[v] = good[p]; subtreeRoot[e] = v; } int getFurthest(int n, vector<vector<int>>& adj, int root) { dfs(n, adj, root, preVisit); int ans = 0; for (int i = 1; i < n; i++) if (depth[i] > depth[ans]) ans = i; return ans; } int ans[N]; struct Node { Node* left = 0; Node* right = 0; int leftValue; int rightValue; bool inverted = false; int goodDepth = 0, badDepth = 0; }; class SegmentTree { public: SegmentTree(int n) { root = buildTree(0, n - 1); } ~SegmentTree() { dispose(root); } void dispose(Node* node) { if (!node) return; dispose(node->left); dispose(node->right); delete node; } Node* buildTree(int l, int r) { Node* node = new Node(); node->leftValue = l; node->rightValue = r; if (l < r) { int mid = (l + r) / 2; node->left = buildTree(l, mid); node->right = buildTree(mid + 1, r); } return node; } void setDepth(int ind, int depth, bool good) { setDepth(root, ind, depth, good); } void setDepth(Node* node, int ind, int depth, bool good) { if (node->rightValue == ind && node->leftValue == ind) { if (good) node->goodDepth = depth; else node->badDepth = depth; return; } if (ind <= node->left->rightValue) setDepth(node->left, ind, depth, good); else setDepth(node->right, ind, depth, good); node->goodDepth = max(node->left->goodDepth, node->right->goodDepth); node->badDepth = max(node->left->badDepth, node->right->badDepth); } void addSegment(int left, int right) { addSegment(root, left, right); } void pushLazy(Node* node) { if (node->inverted) { swap(node->goodDepth, node->badDepth); if (node->left) node->left->inverted = !node->left->inverted; if (node->right) node->right->inverted = !node->right->inverted; node->inverted = false; } } void addSegment(Node* node, int left, int right) { if (node->rightValue < left || node->leftValue > right) return; if (left <= node->leftValue && right >= node->rightValue) { node->inverted = !node->inverted; return; } pushLazy(node); addSegment(node->left, left, right); addSegment(node->right, left, right); node->goodDepth = node->badDepth = 0; if (node->left) { pushLazy(node->left); node->goodDepth = node->left->goodDepth; node->badDepth = node->left->badDepth; } if (node->right) { pushLazy(node->right); node->goodDepth = max(node->goodDepth, node->right->goodDepth); node->badDepth = max(node->badDepth, node->right->badDepth); } } int query(int left, int right) { return query(root, left, right); } int query(Node* node, int left, int right) { if (!node || node->rightValue < left || node->leftValue > right) return 0; pushLazy(node); if (left <= node->leftValue && right >= node->rightValue) { return node->goodDepth; } return max(query(node->left, left, right), query(node->right, left, right)); } Node* root; }; void solve(int n, vector<vector<int>>& adj, int root) { curorder = 0; dfs(n, adj, root, preVisit, postVisit, traverseTreeEdge); SegmentTree tree(n); for (int i = 0; i < n; i++) tree.setDepth(preorder[i], depth[i], good[i]); for (int i = 0; i < q; i++) { int v = subtreeRoot[qind[i]]; tree.addSegment(preorder[v], postorder[v]); ans[i] = max(ans[i], tree.query(0, n - 1)); } } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n; cin >> n; vector<vector<int>> adj(n); for (int i = 0; i < n - 1; i++) { cin >> s[i] >> t[i] >> type[i]; s[i]--; t[i]--; adj[s[i]].push_back(i); adj[t[i]].push_back(i); } cin >> q; for (int i = 0; i < q; i++) { cin >> qind[i]; qind[i]--; } int v1 = getFurthest(n, adj, 0); int v2 = getFurthest(n, adj, v1); memset(ans, 0, sizeof(ans)); solve(n, adj, v1); solve(n, adj, v2); for (int i = 0; i < q; i++) cout << ans[i] << "\n"; return 0; }
#include <bits/stdc++.h> using namespace std; using LL = long long; using ULL = unsigned long long; using pii = pair<int, int>; using PLL = pair<LL, LL>; using UI = unsigned int; const int mod = 1e9 + 7; const int inf = 0x3f3f3f3f; const double EPS = 1e-8; const double PI = acos(-1.0); const int N = 5e5 + 10; int n, Q, dfs_cnt; bool edge[N]; vector<pii> V[N]; int buf[N]; bool tag[N]; struct Tree { int lft[N], rgt[N], bottom[N], l[N << 2], r[N << 2], S[N << 2][2]; bool lazy[N << 2]; void dfs(int x, int fa, int dep, bool f) { lft[x] = ++dfs_cnt; buf[dfs_cnt] = dep; tag[dfs_cnt] = f; for (auto p : V[x]) { if (p.first == fa) continue; bottom[p.second] = p.first; dfs(p.first, x, dep + 1, f ^ edge[p.second]); } rgt[x] = dfs_cnt; } void build(int o, int ll, int rr) { l[o] = ll; r[o] = rr; lazy[o] = 0; if (ll < rr) { int mid = l[o] + r[o] >> 1; build(o << 1, ll, mid); build(o << 1 | 1, mid + 1, rr); S[o][0] = max(S[o << 1][0], S[o << 1 | 1][0]); S[o][1] = max(S[o << 1][1], S[o << 1 | 1][1]); } else { if (tag[ll]) { S[o][0] = 0; S[o][1] = buf[ll]; } else { S[o][0] = buf[ll]; S[o][1] = 0; } } } int pushdown(int o) { int mid = l[o] + r[o] >> 1; if (lazy[o]) { update(o << 1, l[o], mid); update(o << 1 | 1, mid + 1, r[o]); lazy[o] = 0; } return mid; } void update(int o, int ll, int rr) { if (l[o] == ll && r[o] == rr) { lazy[o] ^= 1; swap(S[o][0], S[o][1]); return; } int mid = pushdown(o); if (rr <= mid) update(o << 1, ll, rr); else if (ll > mid) update(o << 1 | 1, ll, rr); else { update(o << 1, ll, mid); update(o << 1 | 1, mid + 1, rr); } S[o][0] = max(S[o << 1][0], S[o << 1 | 1][0]); S[o][1] = max(S[o << 1][1], S[o << 1 | 1][1]); } void init(int x) { dfs_cnt = 0; dfs(x, -1, 0, 0); build(1, 1, n); } void flip(int x) { x = bottom[x]; update(1, lft[x], rgt[x]); } } tree[2]; int dist[N]; int bfs(int x) { for (int i = (1); i < (n + 1); ++i) dist[i] = inf; dist[x] = 0; int ret = x; queue<int> Q; Q.emplace(x); while (!Q.empty()) { x = Q.front(); Q.pop(); if (dist[x] > dist[ret]) ret = x; for (pii p : V[x]) { if (dist[p.first] == inf) { dist[p.first] = dist[x] + 1; Q.emplace(p.first); } } } return ret; } int main() { int x, y, z; scanf("%d", &n); for (int i = (1); i < (n); ++i) { scanf("%d %d %d", &x, &y, &z); V[x].emplace_back(y, i); V[y].emplace_back(x, i); edge[i] = z; } x = bfs(1); y = bfs(x); tree[0].init(x); tree[1].init(y); scanf("%d", &Q); while (Q--) { scanf("%d", &x); tree[0].flip(x); tree[1].flip(x); printf("%d\n", max(tree[0].S[1][0], tree[1].S[1][0])); } return 0; }
#include <bits/stdc++.h> using namespace std; vector<pair<int, int> > AdjList[500005]; int id[500005]; int A[500005]; int B[500005]; int T[500005]; int ans[500005]; int n, m; int dist1[500005]; int dist2[500005]; int indx[500005]; int right1[500005]; int inv[500005]; bool visited[500005]; int cnt; void dfs(int u, int d1, int d2) { if (visited[u]) { return; } visited[u] = true; dist1[u] = d1; dist2[u] = d2; indx[u] = cnt; inv[cnt] = u; cnt++; for (pair<int, int> v : AdjList[u]) { if (!visited[v.first]) { dfs(v.first, d1 + 1, d2 ^ v.second); } } right1[u] = cnt - 1; } int findFurthestVertex(int root) { for (int i = 1; i <= n; i++) { visited[i] = 0; } cnt = 1; dfs(root, 0, 0); int maxDist = -1; int bestVertex = -1; for (int i = 1; i <= n; i++) { if (dist1[i] > maxDist) { maxDist = dist1[i]; bestVertex = i; } } return bestVertex; } int max0[(1 << 20) + 5]; int max1[(1 << 20) + 5]; int lazyterbalik[(1 << 20) + 5]; void init(int i = 1, int s = 1, int e = n) { if (s == e) { lazyterbalik[i] = 0; if (dist2[inv[s]] == 0) { max0[i] = dist1[inv[s]]; max1[i] = -1; } else { max1[i] = dist1[inv[s]]; max0[i] = -1; } return; } else { int l = (i << 1); int r = (i << 1) | 1; int m = (s + e) >> 1; init(l, s, m); init(r, m + 1, e); max0[i] = max(max0[l], max0[r]); max1[i] = max(max1[l], max1[r]); lazyterbalik[i] = 0; } } void propagate(int i, int s, int e) { if (lazyterbalik[i]) { if (s == e) { swap(max0[i], max1[i]); lazyterbalik[i] = 0; return; } else { int l = (i << 1); int r = (i << 1) | 1; lazyterbalik[l] ^= 1; lazyterbalik[r] ^= 1; swap(max0[i], max1[i]); lazyterbalik[i] = 0; return; } } } void update(int x, int y, int i = 1, int s = 1, int e = n) { propagate(i, s, e); if (x <= s && e <= y) { lazyterbalik[i] ^= 1; return; } else { int l = (i << 1); int r = (i << 1) | 1; int m = (s + e) >> 1; if (x > m) { update(x, y, r, m + 1, e); } else if (y <= m) { update(x, y, l, s, m); } else { update(x, y, l, s, m); update(x, y, r, m + 1, e); } propagate(l, s, m); propagate(r, m + 1, e); max0[i] = max(max0[l], max0[r]); max1[i] = max(max1[l], max1[r]); } } int query() { propagate(1, 1, n); return max0[1]; } void findAns(int root) { findFurthestVertex(root); init(); for (int i = 1; i <= m; i++) { int u = A[id[i]]; int v = B[id[i]]; if (dist1[u] < dist1[v]) { swap(u, v); } update(indx[u], right1[u]); ans[i] = max(ans[i], query()); } } int main() { scanf("%d", &n); for (int i = 1; i < n; i++) { scanf("%d%d%d", &A[i], &B[i], &T[i]); AdjList[A[i]].push_back(pair<int, int>(B[i], T[i])); AdjList[B[i]].push_back(pair<int, int>(A[i], T[i])); } scanf("%d", &m); for (int i = 1; i <= m; i++) { scanf("%d", &id[i]); } memset(ans, -1, sizeof(ans)); int root = findFurthestVertex(1); findAns(root); int root2 = findFurthestVertex(root); findAns(root2); for (int i = 1; i <= m; i++) { printf("%d\n", ans[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; namespace io { const int BUFSIZE = 1 << 20; char ibuf[BUFSIZE + 1], *is = ibuf, *it = ibuf; char obuf[BUFSIZE + 1], *os = obuf, *ot = obuf + BUFSIZE; inline char read_char() { if (is == it) { it = (is = ibuf) + fread(ibuf, 1, BUFSIZE, stdin); if (is == it) *it++ = EOF; } return *is++; } template <class T> inline void read_int(T &x) { T f = 1; char c = read_char(); while (!isdigit(c)) { if (c == '-') f = -1; c = read_char(); } x = 0; while (isdigit(c)) { x = x * 10 + c - '0'; c = read_char(); } x *= f; } inline void read_str(char *s) { char c = read_char(); while (c <= ' ') { c = read_char(); } while (c > ' ') { *s++ = c; c = read_char(); } *s = 0; } inline void flush() { fwrite(obuf, 1, os - obuf, stdout); os = obuf; } inline void print_char(char c) { *os++ = c; if (os == ot) { flush(); } } template <class T> inline void print_int(T x, char c = 0) { static char q[40]; if (!x) { print_char('0'); } else { if (x < 0) { print_char('-'); x = -x; } int top = 0; while (x) { q[top++] = x % 10 + '0'; x /= 10; } while (top--) { print_char(q[top]); } } if (c) print_char(c); } inline void print_str(char *s, char c = 0) { while (*s) { print_char(*s++); } if (c) print_char(c); } struct flusher_t { inline ~flusher_t() { flush(); } } flusher; } // namespace io using io::print_char; using io::print_int; using io::print_str; using io::read_char; using io::read_int; using io::read_str; const int N = 500005; int n, Q, tot, dfn[N], dl[N], pp[N], dr[N], dfc, st[20][N * 2], lg2[N * 2], dep[N], dist[N]; vector<pair<int, int> > G[N]; inline int LCA(int l, int r) { l = dfn[l], r = dfn[r]; if (l > r) swap(l, r); int i = lg2[r - l + 1]; if (dep[st[i][l]] < dep[st[i][r - (1 << i) + 1]]) return st[i][l]; else return st[i][r - (1 << i) + 1]; } inline int getdist(int u, int v) { return dep[u] + dep[v] - 2 * dep[LCA(u, v)]; } struct Node { int u, v, d; }; inline Node Merge(const Node &a, const Node &b) { if (a.d == -1) return b; if (b.d == -1) return a; Node ret; if (a.d > b.d) { ret = a; } else { ret = b; } int d1 = getdist(a.u, b.u), d2 = getdist(a.u, b.v), d3 = getdist(a.v, b.u), d4 = getdist(a.v, b.v); int md = max(max(d1, d2), max(d3, d4)); if (md <= ret.d) return ret; ret.d = md; if (d1 == md) { ret.u = a.u; ret.v = b.u; } else if (d2 == md) { ret.u = a.u; ret.v = b.v; } else if (d3 == md) { ret.u = a.v; ret.v = b.u; } else { ret.u = a.v; ret.v = b.v; } return ret; } Node tr[N * 4][2]; int tag[N * 4]; void build(int i, int l, int r) { tag[i] = 0; if (l == r) { int u = pp[l]; tr[i][dist[u]].u = tr[i][dist[u]].v = u; tr[i][dist[u]].d = 0; tr[i][dist[u] ^ 1].u = tr[i][dist[u] ^ 1].v = 0; tr[i][dist[u] ^ 1].d = -1; return; } int mid = (l + r) >> 1; build(i << 1, l, mid); build(i << 1 | 1, mid + 1, r); tr[i][0] = Merge(tr[i << 1][0], tr[i << 1 | 1][0]); tr[i][1] = Merge(tr[i << 1][1], tr[i << 1 | 1][1]); } inline void pushdown(int i) { if (tag[i]) { swap(tr[i << 1][0], tr[i << 1][1]); swap(tr[i << 1 | 1][0], tr[i << 1 | 1][1]); tag[i << 1] ^= 1; tag[i << 1 | 1] ^= 1; tag[i] = 0; } } void modify(int i, int l, int r, int lf, int rg) { if (lf <= l && r <= rg) { swap(tr[i][0], tr[i][1]); tag[i] ^= 1; return; } pushdown(i); int mid = (l + r) >> 1; if (lf <= mid) modify(i << 1, l, mid, lf, rg); if (rg > mid) modify(i << 1 | 1, mid + 1, r, lf, rg); tr[i][0] = Merge(tr[i << 1][0], tr[i << 1 | 1][0]); tr[i][1] = Merge(tr[i << 1][1], tr[i << 1 | 1][1]); } void dfs(int u, int lst, int depth, int D) { dl[u] = ++dfc; pp[dfc] = u; st[0][dfn[u] = ++tot] = u; dep[u] = depth; dist[u] = D; for (auto &e : G[u]) { int v = e.first; if (v == lst) continue; dfs(v, u, depth + 1, D ^ e.second); st[0][++tot] = u; } dr[u] = dfc; } int eu[N], ev[N]; int main() { read_int(n); for (int i = 1; i < n; i++) { int u, v, w; read_int(u); eu[i] = u; read_int(v); ev[i] = v; read_int(w); G[u].push_back(make_pair(v, w)); G[v].push_back(make_pair(u, w)); } tot = 0; dfs(1, 0, 0, 0); lg2[0] = -1; for (int i = 1; i <= tot; i++) lg2[i] = lg2[i - 1] + ((i & (i - 1)) ? 0 : 1); for (int i = 1; i < 20; i++) { for (int j = 1; j <= tot - (1 << i) + 1; j++) { if (dep[st[i - 1][j]] < dep[st[i - 1][j + (1 << (i - 1))]]) st[i][j] = st[i - 1][j]; else st[i][j] = st[i - 1][j + (1 << (i - 1))]; } } build(1, 1, n); read_int(Q); for (int i = 1; i < n; i++) { if (dl[eu[i]] > dl[ev[i]]) swap(eu[i], ev[i]); } while (Q--) { int eid; read_int(eid); modify(1, 1, n, dl[ev[eid]], dr[ev[eid]]); print_int(max(tr[1][0].d, tr[1][1].d), '\n'); } return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 1e6; int n, x[555555], y[555555], t[555555], cnt, beg[555555], en[555555], dep[555555], crt, vl[555555], b[555555], e[555555], id, Log[1111111], ww[555555], q; struct treenode { int lazy, x0, y0, x1, y1, mx0, mx1; treenode() { x0 = y0 = x1 = y1 = -1; mx0 = mx1 = -1e9; lazy = 0; } } tree[2222222]; vector<pair<int, int> > g[555555]; int arr[1111111], st[22][1111111]; void dfs(int i, int fa) { dep[i] = dep[fa] + 1; beg[i] = ++cnt; for (int j = 0; j < g[i].size(); j++) { int to = g[i][j].first, val = g[i][j].second; if (to == fa) continue; vl[to] = vl[i] ^ val; dfs(to, i); } en[i] = cnt; } void rfs(int i, int fa) { ++crt; b[i] = crt; arr[crt] = dep[i]; for (int j = 0; j < g[i].size(); j++) { int to = g[i][j].first; if (to == fa) continue; rfs(to, i); ++crt; arr[crt] = dep[i]; } e[i] = crt; } int get(int l, int r) { int x = Log[r - l + 1]; return min(st[x][l], st[x][r - (1 << x) + 1]); } int dist(int x, int y) { if (x == -1 || y == -1) return -1e9; if (b[x] > b[y]) swap(x, y); return dep[x] + dep[y] - (get(b[x], e[y]) << 1); } void pushup(int node) { int mx = -2e9, cr; if (tree[node << 1].mx0 > mx) { mx = tree[node << 1].mx0; tree[node].x0 = tree[node << 1].x0; tree[node].y0 = tree[node << 1].y0; } if (tree[(node << 1) | 1].mx0 > mx) { mx = tree[(node << 1) | 1].mx0; tree[node].x0 = tree[(node << 1) | 1].x0; tree[node].y0 = tree[(node << 1) | 1].y0; } cr = dist(tree[node << 1].x0, tree[(node << 1) | 1].x0); if (cr > mx) { mx = cr; tree[node].x0 = tree[node << 1].x0; tree[node].y0 = tree[(node << 1) | 1].x0; } cr = dist(tree[node << 1].x0, tree[(node << 1) | 1].y0); if (cr > mx) { mx = cr; tree[node].x0 = tree[node << 1].x0; tree[node].y0 = tree[(node << 1) | 1].y0; } cr = dist(tree[node << 1].y0, tree[(node << 1) | 1].x0); if (cr > mx) { mx = cr; tree[node].x0 = tree[node << 1].y0; tree[node].y0 = tree[(node << 1) | 1].x0; } cr = dist(tree[node << 1].y0, tree[(node << 1) | 1].y0); if (cr > mx) { mx = cr; tree[node].x0 = tree[node << 1].y0; tree[node].y0 = tree[(node << 1) | 1].y0; } tree[node].mx0 = mx; mx = -2e9; if (tree[node << 1].mx1 > mx) { mx = tree[node << 1].mx1; tree[node].x1 = tree[node << 1].x1; tree[node].y1 = tree[node << 1].y1; } if (tree[(node << 1) | 1].mx1 > mx) { mx = tree[(node << 1) | 1].mx1; tree[node].x1 = tree[(node << 1) | 1].x1; tree[node].y1 = tree[(node << 1) | 1].y1; } cr = dist(tree[node << 1].x1, tree[(node << 1) | 1].x1); if (cr > mx) { mx = cr; tree[node].x1 = tree[node << 1].x1; tree[node].y1 = tree[(node << 1) | 1].x1; } cr = dist(tree[node << 1].x1, tree[(node << 1) | 1].y1); if (cr > mx) { mx = cr; tree[node].x1 = tree[node << 1].x1; tree[node].y1 = tree[(node << 1) | 1].y1; } cr = dist(tree[node << 1].y1, tree[(node << 1) | 1].x1); if (cr > mx) { mx = cr; tree[node].x1 = tree[node << 1].y1; tree[node].y1 = tree[(node << 1) | 1].x1; } cr = dist(tree[node << 1].y1, tree[(node << 1) | 1].y1); if (cr > mx) { mx = cr; tree[node].x1 = tree[node << 1].y1; tree[node].y1 = tree[(node << 1) | 1].y1; } tree[node].mx1 = mx; } void push(int node) { tree[node].lazy ^= 1; swap(tree[node].x0, tree[node].x1); swap(tree[node].y0, tree[node].y1); swap(tree[node].mx0, tree[node].mx1); } void pushdown(int node) { if (tree[node].lazy) { push(node << 1); push((node << 1) | 1); tree[node].lazy = 0; } } void build(int l, int r, int node) { if (l == r) { if (vl[ww[l]] == 1) { tree[node].x0 = tree[node].y0 = ww[l]; tree[node].x1 = tree[node].y1 = -1; tree[node].mx0 = 0; tree[node].mx1 = -1e9; } else { tree[node].x1 = tree[node].y1 = ww[l]; tree[node].x0 = tree[node].y0 = -1; tree[node].mx0 = -1e9; tree[node].mx1 = 0; } return; } int mid = (l + r) >> 1; build(l, mid, node << 1); build(mid + 1, r, (node << 1) | 1); pushup(node); } void update(int beg, int en, int l, int r, int node) { if (l > en || r < beg) return; if (l >= beg && r <= en) { push(node); return; } int mid = (l + r) >> 1; pushdown(node); update(beg, en, l, mid, node << 1); update(beg, en, mid + 1, r, (node << 1) | 1); pushup(node); } int main() { scanf("%d", &n); for (int i = 1; i < n; i++) { scanf("%d%d%d", &x[i], &y[i], &t[i]); g[x[i]].push_back(make_pair(y[i], t[i])); g[y[i]].push_back(make_pair(x[i], t[i])); } dfs(1, 0); rfs(1, 0); for (int i = 2; i <= maxn; i++) Log[i] = Log[i >> 1] + 1; for (int i = 1; i <= crt; i++) st[0][i] = arr[i]; for (int i = 1; i <= 20; i++) { for (int j = 1; j <= crt; j++) { st[i][j] = st[i - 1][j]; if (j + (1 << (i - 1)) <= crt) st[i][j] = min(st[i][j], st[i - 1][j + (1 << (i - 1))]); } } for (int i = 1; i <= n; i++) ww[beg[i]] = i; build(1, n, 1); scanf("%d", &q); while (q--) { scanf("%d", &id); if (dep[x[id]] < dep[y[id]]) swap(x[id], y[id]); update(beg[x[id]], en[x[id]], 1, n, 1); printf("%d\n", max(tree[1].mx0, tree[1].mx1)); } return 0; }
#include <bits/stdc++.h> using namespace std; const int next_x[8] = {0, 1, -1, 0, 1, 1, -1, -1}; const int next_y[8] = {1, 0, 0, -1, 1, -1, -1, 1}; const int inf = 1e9 + 5; const long long linf = 1e18 + 5; const double PI = acos(-1.0); const int MAXN = 1e6 + 5; const int N = 4e6 + 5; const long double eps = 1e-8; const long double fix = 1e-2; namespace io { const int SIZE = (1 << 21) + 1; char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c, qu[55]; int f, qr; inline void flush() { fwrite(obuf, 1, oS - obuf, stdout); oS = obuf; } inline void putc(char x) { *oS++ = x; if (oS == oT) flush(); } template <typename A> inline bool read(A &x) { for (f = 1, c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++); c < '0' || c > '9'; c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) if (c == '-') f = -1; else if (c == EOF) return 0; for (x = 0; c <= '9' && c >= '0'; c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) x = x * 10 + (c & 15); x *= f; return 1; } inline bool read(char &x) { while ((x = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) == ' ' || x == '\n' || x == '\r') ; return x != EOF; } inline bool read(char *x) { while ((*x = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++)) == '\n' || *x == ' ' || *x == '\r') ; if (*x == EOF) return 0; while (!(*x == '\n' || *x == ' ' || *x == '\r' || *x == EOF)) *(++x) = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++); *x = 0; return 1; } template <typename A, typename... B> inline bool read(A &x, B &...y) { return read(x) && read(y...); } template <typename A> inline bool write(A x) { if (!x) putc('0'); if (x < 0) putc('-'), x = -x; while (x) qu[++qr] = x % 10 + '0', x /= 10; while (qr) putc(qu[qr--]); return 0; } inline bool write(char x) { putc(x); return 0; } inline bool write(const char *x) { while (*x) { putc(*x); ++x; } return 0; } inline bool write(char *x) { while (*x) { putc(*x); ++x; } return 0; } template <typename A, typename... B> inline bool write(A x, B... y) { return write(x) || write(y...); } struct Flusher_ { ~Flusher_() { flush(); } } io_flusher_; } // namespace io namespace seg { int mx[MAXN * 4][2], rev[MAXN * 4]; void dorev(int cnt) { rev[cnt] ^= 1, swap(mx[cnt][0], mx[cnt][1]); } void up(int cnt) { for (int k = (0), I = (1) + 1; k < I; ++k) mx[cnt][k] = max(mx[(cnt << 1)][k], mx[(cnt << 1 | 1)][k]); } void down(int cnt) { if (rev[cnt]) dorev((cnt << 1)), dorev((cnt << 1 | 1)), rev[cnt] = 0; } void build(int l, int r, int a[], int d[], int cnt) { rev[cnt] = 0; if (l == r) { mx[cnt][a[l]] = d[l], mx[cnt][!a[l]] = 0; return; } build(l, ((l + r) / 2), a, d, (cnt << 1)), build(((l + r) / 2) + 1, r, a, d, (cnt << 1 | 1)), up(cnt); } void flip(int l, int r, int nl, int nr, int cnt) { if (l == nl && r == nr) return dorev(cnt); down(cnt); if (nr <= ((l + r) / 2)) flip(l, ((l + r) / 2), nl, nr, (cnt << 1)); else if (nl > ((l + r) / 2)) flip(((l + r) / 2) + 1, r, nl, nr, (cnt << 1 | 1)); else flip(l, ((l + r) / 2), nl, ((l + r) / 2), (cnt << 1)), flip(((l + r) / 2) + 1, r, ((l + r) / 2) + 1, nr, (cnt << 1 | 1)); up(cnt); } } // namespace seg int n, m, tim = 0; int u[MAXN], v[MAXN], w[MAXN], q[MAXN]; int a[MAXN], d[MAXN], _a[MAXN], _d[MAXN], ans[MAXN], st[MAXN], ed[MAXN], node[MAXN]; struct edge { int u, v, w, next; } e[MAXN * 2]; int pre[MAXN], edge_cnt = 0; void addedge(int u, int v, int w = 0) { edge_cnt = edge_cnt + 1, e[edge_cnt].u = u, e[edge_cnt].v = v, e[edge_cnt].w = w, e[edge_cnt].next = pre[u], pre[u] = edge_cnt; }; void dfs(int u, int fa) { st[u] = ++tim, node[tim] = u, d[u] = d[fa] + 1; for (long long i = pre[u], v = e[i].v, w = e[i].w; i; i = e[i].next, v = e[i].v, w = e[i].w) if (v != fa) a[v] = a[u] ^ w, dfs(v, u); ed[u] = tim; } void solve(int root) { tim = 0, a[root] = 0, d[0] = -1, dfs(root, 0); for (int i = (1), I = (n) + 1; i < I; ++i) _a[i] = a[node[i]], _d[i] = d[node[i]]; seg::build(1, n, _a, _d, 1); for (int i = (1), I = (m) + 1; i < I; ++i) { int x = d[u[q[i]]] > d[v[q[i]]] ? u[q[i]] : v[q[i]]; seg::flip(1, n, st[x], ed[x], 1), ans[i] = max(ans[i], seg::mx[1][0]); } } int find(int u, int fa) { int ans = u; d[u] = d[fa] + 1; for (int i = pre[u], v = e[i].v; i; i = e[i].next, v = e[i].v) if (v != fa) { int res = find(v, u); if (d[res] > d[ans]) ans = res; } return ans; } int work() { io::read(n); for (int i = (1), I = (n - 1) + 1; i < I; ++i) { io::read(u[i]), io::read(v[i]), io::read(w[i]); addedge(u[i], v[i], w[i]), addedge(v[i], u[i], w[i]); } io::read(m); for (int i = (1), I = (m) + 1; i < I; ++i) io::read(q[i]); int root; solve(root = find(1, 0)), solve(find(root, 0)); for (int i = (1), I = (m) + 1; i < I; ++i) io::write(ans[i]), io::write('\n'); io::flush(); return 0; } int main() { work(); return 0; }
#include <bits/stdc++.h> #pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") using namespace std; int n, m, r1, r2, t1[2000005][2], t2[2000005][2], d1[500005], a1[500005], d2[500005], a2[500005]; int i1[500005], o1[500005], i2[500005], o2[500005], st, s1[500005], s2[500005], L, R; int f1[500005], f2[500005]; bool b1[2000005], b2[2000005]; vector<int> v[500005], e[500005], ve[500005]; int mx(int x, int y) { return x > y ? x : y; } void dfs(int x, int y) { d1[x] = d1[y] + 1; i1[x] = ++st; s1[st] = x; for (int i = 0; i < v[x].size(); ++i) { int z = v[x][i]; if (z != y) { a1[z] = a1[x] ^ e[x][i]; f1[ve[x][i]] = z; dfs(z, x); } } o1[x] = st; } void bld1(int k, int l, int r) { if (l == r) { t1[k][a1[s1[l]]] = d1[s1[l]]; return; } int m = (l + r) >> 1, lc = k << 1, rc = lc ^ 1; bld1(lc, l, m), bld1(rc, m + 1, r); t1[k][0] = mx(t1[lc][0], t1[rc][0]); t1[k][1] = mx(t1[lc][1], t1[rc][1]); } void bld2(int k, int l, int r) { if (l == r) { t2[k][a2[s2[l]]] = d2[s2[l]]; return; } int m = (l + r) >> 1, lc = k << 1, rc = lc ^ 1; bld2(lc, l, m), bld2(rc, m + 1, r); t2[k][0] = mx(t2[lc][0], t2[rc][0]); t2[k][1] = mx(t2[lc][1], t2[rc][1]); } void mk1(int k, int l, int r) { if (l >= L && r <= R) { b1[k] ^= 1; swap(t1[k][0], t1[k][1]); return; } int m = (l + r) >> 1, lc = k << 1, rc = lc ^ 1; if (b1[k]) { b1[lc] ^= 1; swap(t1[lc][0], t1[lc][1]); b1[rc] ^= 1; swap(t1[rc][0], t1[rc][1]); b1[k] = 0; } if (L <= m) mk1(lc, l, m); if (R > m) mk1(rc, m + 1, r); t1[k][0] = mx(t1[lc][0], t1[rc][0]); t1[k][1] = mx(t1[lc][1], t1[rc][1]); } void mk2(int k, int l, int r) { if (l >= L && r <= R) { b2[k] ^= 1; swap(t2[k][0], t2[k][1]); return; } int m = (l + r) >> 1, lc = k << 1, rc = lc ^ 1; if (b2[k]) { b2[lc] ^= 1; swap(t2[lc][0], t2[lc][1]); b2[rc] ^= 1; swap(t2[rc][0], t2[rc][1]); b2[k] = 0; } if (L <= m) mk2(lc, l, m); if (R > m) mk2(rc, m + 1, r); t2[k][0] = mx(t2[lc][0], t2[rc][0]); t2[k][1] = mx(t2[lc][1], t2[rc][1]); } int main() { scanf("%d", &n); for (int i = 1; i < n; ++i) { int x, y, z; scanf("%d%d%d", &x, &y, &z); v[x].push_back(y), v[y].push_back(x); e[x].push_back(z), e[y].push_back(z); ve[x].push_back(i), ve[y].push_back(i); } dfs(1, 0); r2 = 1; for (int i = 1; i <= n; ++i) if (d1[i] > d1[r2]) r2 = i; a1[r2] = 0; st = 0; dfs(r2, 0); for (int i = 1; i <= n; ++i) if (d1[i] > d1[r1]) r1 = i; for (int i = 1; i <= n; ++i) a2[i] = a1[i], d2[i] = d1[i], i2[i] = i1[i], o2[i] = o1[i], s2[i] = s1[i], f2[i] = f1[i]; a1[r1] = 0; st = 0; dfs(r1, 0); bld1(1, 1, n); bld2(1, 1, n); scanf("%d", &m); while (m--) { int x; scanf("%d", &x); L = i1[f1[x]], R = o1[f1[x]]; mk1(1, 1, n); L = i2[f2[x]], R = o2[f2[x]]; mk2(1, 1, n); printf("%d\n", mx(t1[1][0], t2[1][0]) - 1); } return 0; }
#include <bits/stdc++.h> using namespace std; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); inline long long rand(long long x, long long y) { return rng() % (y + 1 - x) + x; } string inline to_string(char c) { string second(1, c); return second; } template <typename T> inline T gcd(T a, T b) { return a == 0 ? llabs(b) : gcd(b % a, a); } using ll = long long; using ld = long double; using pi = pair<ll, ll>; using spi = pair<ll, pi>; using dpi = pair<pi, pi>; long long LLINF = 1e18; int INF = 1e9 + 1e6; ll n, m; bool on[(500006)]; vector<pi> v[(500006)]; pi E[(500006)]; struct tree { int r, st[(500006)], en[(500006)], co, dist[(500006)]; bool par[(500006)]; struct node { int second, e, m; ll mx[2]; bool flip; node *l, *r; node(int S, int E) { second = S, e = E, m = (second + e) >> 1; mx[0] = mx[1] = flip = 0; if (second ^ e) l = new node(second, m), r = new node(m + 1, e); } void update(int x, int y) { if (second == x && e == y) { flip ^= 1; return; } if (x > m) r->update(x, y); else if (y <= m) l->update(x, y); else l->update(x, m), r->update(m + 1, y); l->value(), r->value(); for (ll i = 0; i <= ll(1); ++i) mx[i] = max(l->mx[i], r->mx[i]); } void set(int x, pi nval) { if (second == e) { mx[nval.first] = max(mx[nval.first], nval.second); return; } if (x > m) r->set(x, nval); else l->set(x, nval); for (ll i = 0; i <= ll(1); ++i) mx[i] = max(l->mx[i], r->mx[i]); } void value() { if (!flip) return; flip = 0; swap(mx[0], mx[1]); if (second ^ e) l->flip ^= 1, r->flip ^= 1; } void pt() { value(); if (second ^ e) l->pt(), r->pt(); cerr << second << ' ' << m << ' ' << e << ": " << mx[0] << ' ' << mx[1] << '\n'; } } * seg; void init(int _r) { r = _r; seg = new node(1, n), co = 1; function<void(ll, ll)> dfs = [&](ll x, ll p) { st[x] = co++; for (auto i : v[x]) if (i.first ^ p) par[i.first] = par[x] ^ on[i.second], dist[i.first] = dist[x] + 1, dfs(i.first, x); en[x] = co - 1; }; par[r] = 0, dist[r] = 0, dfs(r, r); for (ll i = 1; i <= ll(n); ++i) seg->set(st[i], {par[i], dist[i]}); } void flip(int id) { int a = E[id].first, b = E[id].second; if (st[a] > st[b]) swap(a, b); seg->update(st[b], en[b]); } ll ans() { seg->value(); return seg->mx[0]; } } A, B; pi diam() { ll r1 = 1, r2 = 1, mx = 0; function<void(ll, ll, ll)> dfs = [&](ll x, ll p, ll d) { if (d > mx) r1 = x, mx = d; for (auto i : v[x]) if (i.first ^ p) dfs(i.first, x, d + 1); }; dfs(1, 1, 0); r2 = r1, mx = 0; dfs(r2, r2, 0); return pi(r1, r2); } int main() { ios_base::sync_with_stdio(false); cin.tie(0); cin >> n; for (ll i = 1; i <= ll(n - 1); ++i) { ll a, b; cin >> a >> b >> on[i]; v[a].emplace_back(b, i), v[b].emplace_back(a, i); E[i] = {a, b}; } pi nodes = diam(); A.init(nodes.first), B.init(nodes.second); cin >> m; while (m--) { int id; cin >> id; A.flip(id), B.flip(id); on[id] ^= 1; cout << max(A.ans(), B.ans()) << '\n'; } }
#include <bits/stdc++.h> const int N = 500005, L = N << 1, INF = 0x3f3f3f3f; int n, q; struct Edge { int v, w, id; }; std::vector<Edge> E[N]; int son[N]; int dep[N], sum[N]; int st[N], ed[N]; int idt[L], idx; void dfs(int u, int fa) { idt[++idx] = u; st[u] = idx; for (auto e : E[u]) { if (e.v != fa) { son[e.id] = e.v; dep[e.v] = dep[u] + 1; sum[e.v] = sum[u] + e.w; dfs(e.v, u); idt[++idx] = u; } } ed[u] = idx; } struct SegmentTree { static const int N = ::L << 2; int W[N][2], M[N], LM[N][2], MR[N][2], LMR[N][2], tag[N]; void up(int u) { M[u] = std::max(M[u << 1], M[u << 1 | 1]); for (int k = 0; k < 2; ++k) { W[u][k] = std::max(W[u << 1][k], W[u << 1 | 1][k]); LM[u][k] = std::max(LM[u << 1][k], LM[u << 1 | 1][k]); LM[u][k] = std::max(LM[u][k], W[u << 1][k] + M[u << 1 | 1]); MR[u][k] = std::max(MR[u << 1][k], MR[u << 1 | 1][k]); MR[u][k] = std::max(MR[u][k], M[u << 1] + W[u << 1 | 1][k]); LMR[u][k] = std::max(LMR[u << 1][k], LMR[u << 1 | 1][k]); } for (int k1 = 0; k1 < 2; ++k1) { for (int k2 = 0; k2 < 2; ++k2) { LMR[u][k1 ^ k2] = std::max( LMR[u][k1 ^ k2], std::max(LM[u << 1][k1] + W[u << 1 | 1][k2], W[u << 1][k1] + MR[u << 1 | 1][k2])); } } } void rev(int u) { std::swap(W[u][0], W[u][1]); std::swap(LM[u][0], LM[u][1]); std::swap(MR[u][0], MR[u][1]); tag[u] ^= 1; } void down(int u) { if (tag[u]) { rev(u << 1); rev(u << 1 | 1); tag[u] = 0; } } void build(int u, int l, int r) { if (l == r) { int k = sum[idt[l]] & 1; W[u][k] = dep[idt[l]]; M[u] = -2 * dep[idt[l]]; LM[u][k] = MR[u][k] = -dep[idt[l]]; W[u][k ^ 1] = -INF; LM[u][k ^ 1] = MR[u][k ^ 1] = -INF; return; } int mid = (l + r) >> 1; build(u << 1, l, mid); build(u << 1 | 1, mid + 1, r); up(u); } void modify(int u, int l, int r, int L, int R) { if (L <= l && r <= R) { rev(u); return; } int mid = (l + r) >> 1; down(u); if (L <= mid) { modify(u << 1, l, mid, L, R); } if (R > mid) { modify(u << 1 | 1, mid + 1, r, L, R); } up(u); } } T; int main() { std::ios_base::sync_with_stdio(false); std::cin.tie(0); std::cin >> n; for (int i = 1; i < n; ++i) { int u, v, w; std::cin >> u >> v >> w; E[u].push_back({v, w, i}); E[v].push_back({u, w, i}); } dfs(1, 0); T.build(1, 1, idx); std::cin >> q; int dfcmd = 0; while (q--) { int d; std::cin >> d; T.modify(1, 1, idx, st[son[d]], ed[son[d]]); std::cout << T.LMR[1][0] << std::endl; ++dfcmd; } }
#include <bits/stdc++.h> using namespace std; template <typename TH> void _dbg(const char* sdbg, TH h) { cerr << sdbg << "=" << h << "\n"; } template <typename TH, typename... TA> void _dbg(const char* sdbg, TH h, TA... t) { while (*sdbg != ',') { cerr << *sdbg++; } cerr << "=" << h << ","; _dbg(sdbg + 1, t...); } template <class C> void mini(C& a4, C b4) { a4 = min(a4, b4); } template <class C> void maxi(C& a4, C b4) { a4 = max(a4, b4); } template <class T1, class T2> ostream& operator<<(ostream& out, pair<T1, T2> pair) { return out << "(" << pair.first << ", " << pair.second << ")"; } template <class A, class B, class C> struct Triple { A first; B second; C third; bool operator<(const Triple& t) const { if (first != t.first) return first < t.first; if (second != t.second) return second < t.second; return third < t.third; } }; template <class T> void ResizeVec(T&, vector<long long>) {} template <class T> void ResizeVec(vector<T>& vec, vector<long long> sz) { vec.resize(sz[0]); sz.erase(sz.begin()); if (sz.empty()) { return; } for (T& v : vec) { ResizeVec(v, sz); } } template <class A, class B, class C> ostream& operator<<(ostream& out, Triple<A, B, C> t) { return out << "(" << t.first << ", " << t.second << ", " << t.third << ")"; } template <class T> ostream& operator<<(ostream& out, vector<T> vec) { out << "("; for (auto& v : vec) out << v << ", "; return out << ")"; } template <class T> ostream& operator<<(ostream& out, set<T> vec) { out << "("; for (auto& v : vec) out << v << ", "; return out << ")"; } template <class L, class R> ostream& operator<<(ostream& out, map<L, R> vec) { out << "("; for (auto& v : vec) out << v << ", "; return out << ")"; } struct Edge { long long to, id; }; const long long N = 1e6 + 5; vector<Edge> slo[N]; long long ktory; long long vis[N]; long long pre[N][3]; long long sz[N][3]; long long dep[N][3]; const long long M = 1 << 20; long long d; void Dfs(long long v, long long id) { vis[v] = id; sz[v][id] = 1; d++; pre[v][id] = d; for (auto e : slo[v]) { long long nei = e.to; if (vis[nei] == id) { continue; } dep[nei][id] = 1 + dep[v][id]; Dfs(nei, id); sz[v][id] += sz[nei][id]; } } struct Node { long long ma0, ma1, to_push; Node() { ma0 = -N, ma1 = -N; to_push = 0; } }; struct Drz { vector<Node> drz; Drz() { drz.resize(2 * M + 5); } Node& operator[](long long a) { return drz[a]; } void Touch(long long v) { if (drz[v].to_push) { for (long long son = (2 * v); son <= (2 * v + 1); ++son) { drz[son].to_push ^= 1; swap(drz[son].ma0, drz[son].ma1); } } drz[v].to_push = 0; } void Flip(long long bl, long long br, long long l, long long r, long long v) { if (l > br || r < bl) { return; } if (l <= bl && br <= r) { drz[v].to_push ^= 1; swap(drz[v].ma0, drz[v].ma1); return; } Touch(v); long long m = (bl + br) / 2; Flip(bl, m, l, r, 2 * v); Flip(m + 1, br, l, r, 2 * v + 1); drz[v].ma0 = max(drz[2 * v].ma0, drz[2 * v + 1].ma0); drz[v].ma1 = max(drz[2 * v].ma1, drz[2 * v + 1].ma1); } }; Drz drz[3]; int32_t main() { ios_base::sync_with_stdio(0); cout << fixed << setprecision(10); if (0) cout << fixed << setprecision(10); cin.tie(0); long long n; cin >> n; vector<pair<long long, long long> > to_change; vector<pair<long long, long long> > es; for (long long i = (1); i <= (n - 1); ++i) { long long a, b, c; cin >> a >> b >> c; es.push_back({a, b}); slo[a].push_back({b, i}); slo[b].push_back({a, i}); if (c) { to_change.push_back({a, b}); } } for (long long i = (1); i <= (n); ++i) { vis[i] = -1; } d = 0; Dfs(1, 0); long long sr1 = 1; for (long long i = (1); i <= (n); ++i) { if (dep[i][0] > dep[sr1][0]) { sr1 = i; } } d = 0; Dfs(sr1, 1); long long sr2 = 1; for (long long i = (1); i <= (n); ++i) { if (dep[i][1] > dep[sr2][1]) { sr2 = i; } } d = 0; Dfs(sr2, 2); (sr1, sr2); for (long long wh = (1); wh <= (2); ++wh) { for (long long v = (1); v <= (n); ++v) { drz[wh][M - 1 + pre[v][wh]].ma0 = dep[v][wh]; } for (long long i = (M - 1); i >= (1); --i) { drz[wh][i].ma0 = max(drz[wh][2 * i].ma0, drz[wh][2 * i + 1].ma0); } } function<void(long long, long long)> Change = [&](long long a, long long b) { for (long long wh = (1); wh <= (2); ++wh) { if (dep[b][wh] > dep[a][wh]) { swap(a, b); } drz[wh].Flip(1, M, pre[a][wh], pre[a][wh] + sz[a][wh] - 1, 1); } }; for (auto ch : to_change) { Change(ch.first, ch.second); } long long m; cin >> m; for (long long i = (1); i <= (m); ++i) { long long id; cin >> id; long long a = es[id - 1].first; long long b = es[id - 1].second; Change(a, b); (a, b); (drz[1][1].ma0, drz[2][1].ma0); cout << max(drz[1][1].ma0, drz[2][1].ma0) << "\n"; } return 0; }
#include <bits/stdc++.h> int n, m; int x[1111111], y[1111111], l[1111111]; int o[1111111]; std::vector<int> v[1111111]; struct Segt { int mx[4111111][2], r[4111111]; void push(int p) { std::swap(mx[p][0], mx[p][1]), r[p] ^= 1; } void pushd(int p) { if (r[p]) push(p << 1), push(p << 1 | 1), r[p] = 0; } void pushu(int p) { mx[p][0] = std::max(mx[p << 1][0], mx[p << 1 | 1][0]), mx[p][1] = std::max(mx[p << 1][1], mx[p << 1 | 1][1]); } void accord(int* v, int p = 1, int l = 1, int r = n) { if (l == r) { mx[p][0] = v[l]; return; } int mp = (l + r) >> 1; pushd(p), accord(v, p << 1, l, mp), accord(v, p << 1 | 1, mp + 1, r), pushu(p); } void rev(int l, int r, int p = 1, int pl = 1, int pr = n) { if (l > pr || pl > r) return; if (l <= pl && pr <= r) return push(p); int mp = (pl + pr) >> 1; pushd(p), rev(l, r, p << 1, pl, mp), rev(l, r, p << 1 | 1, mp + 1, pr), pushu(p); } }; struct __DFN { Segt T; int dfn[1111111], dfr[1111111], fa[1111111], dep, len[1111111], rel[1111111]; void init(int p, int f = 0) { dfn[p] = ++dep, fa[p] = f, rel[dep] = len[p] = len[f] + 1; for (int t : v[p]) if (t ^ f) init(t, p); dfr[p] = dep; } void reverse(int x, int y) { if (fa[y] == x) x = y; T.rev(dfn[x], dfr[x]); } void build(int px) { init(px), T.accord(rel); register int i; for (i = 1; i < n; i++) if (l[i]) reverse(x[i], y[i]); } } Rol, Ror; int dis[1111111]; void dfs(int p = 1, int f = 0) { dis[p] = dis[f] + 1; for (int t : v[p]) if (t ^ f) dfs(t, p); } void precalc() { dfs(); register int i; int mx = -1, mp = 1; for (i = 1; i <= n; i++) if (dis[i] > mx) mx = dis[i], mp = i; dfs(mp), Rol.build(mp); for (i = 1, mx = -1, mp = 1; i <= n; i++) if (dis[i] > mx) mx = dis[i], mp = i; Ror.build(mp); } void revall(int x, int y) { Rol.reverse(x, y), Ror.reverse(x, y); } void exec() { scanf("%d", &n); register int i; for (i = 1; i < n; i++) scanf("%d%d%d", x + i, y + i, l + i), v[x[i]].push_back(y[i]), v[y[i]].push_back(x[i]); precalc(); scanf("%d", &m); for (i = 1; i <= m; i++) scanf("%d", o + i), revall(x[o[i]], y[o[i]]), printf("%d\n", std::max(Rol.T.mx[1][0], Ror.T.mx[1][0]) - 1); return; } int main() { int T = 1; for (; T--;) exec(); }
#include <bits/stdc++.h> #pragma warning(disable : 4996) template <typename T> T min(T x, T y) { return x < y ? x : y; } template <typename T> T max(T x, T y) { return x > y ? x : y; }; const long long INF = 20000000050000; const long long mod = 1000000007; const int MAXN = 500005; std::pair<int, int> pmax(std::pair<int, int> x, std::pair<int, int> y) { return {max(x.first, y.first), max(x.second, y.second)}; } struct tree { int l; int r; int mx[2]; bool rev; tree *lson; tree *rson; tree() { l = r = 0; mx[0] = -MAXN; mx[1] = -MAXN; rev = false; lson = rson = NULL; } void pushdown() { if (!rev) return; std::swap(lson->mx[0], lson->mx[1]); std::swap(rson->mx[0], rson->mx[1]); lson->rev ^= 1; rson->rev ^= 1; rev = false; } void fix() { mx[0] = max(lson->mx[0], rson->mx[0]); mx[1] = max(lson->mx[1], rson->mx[1]); } void reverse(int L, int R) { if (l >= L && r <= R) { std::swap(mx[0], mx[1]); rev ^= 1; return; } pushdown(); int mid = (l + r) / 2; if (L <= mid) lson->reverse(L, R); if (R > mid) rson->reverse(L, R); fix(); } std::pair<int, int> query(int L, int R) { if (l >= L && r <= R) return {mx[0], mx[1]}; pushdown(); int mid = (l + r) / 2; std::pair<int, int> ans = std::make_pair(-MAXN, -MAXN); if (L <= mid) ans = pmax(ans, lson->query(L, R)); if (R > mid) ans = pmax(ans, rson->query(L, R)); return ans; } void build(int L, int R, int *dep, int *ty) { l = L, r = R; if (l == r) { mx[ty[l] & 1] = dep[l]; return; } int mid = (l + r) / 2; lson = new tree; rson = new tree; lson->build(l, mid, dep, ty); rson->build(mid + 1, r, dep, ty); fix(); } }; int N, u[MAXN], v[MAXN], S1, S2; std::vector<std::pair<int, int> > e[MAXN]; void addedge(int u, int v, int ty) { e[u].push_back({v, ty}); e[v].push_back({u, ty}); } struct STRUCT { tree T; int dep[MAXN], cnt[MAXN], D; int cur, dfn[MAXN], rn[MAXN], rk[MAXN]; void dfs(int v, int f) { if (!f) dep[v] = cnt[v] = cur = D = 0; if (dep[D] < dep[v]) D = v; dfn[v] = ++cur; rk[cur] = v; for (int i = 0; i < e[v].size(); i++) { std::pair<int, int> P = e[v][i]; if (P.first == f) continue; dep[P.first] = dep[v] + 1; cnt[P.first] = cnt[v] + P.second; dfs(P.first, v); } rn[v] = cur; } void prepare(int S1) { static int tdep[MAXN], tcnt[MAXN]; dfs(S1, 0); for (int i = 1; i <= N; i++) { tdep[i] = dep[rk[i]]; tcnt[i] = cnt[rk[i]]; } T.build(1, N, tdep, tcnt); } void update(int u, int v) { int id = dep[u] > dep[v] ? u : v; T.reverse(dfn[id], rn[id]); } }; STRUCT T1, T2; void init() { int t; scanf("%d", &N); for (int i = 1; i < N; i++) { scanf("%d %d %d", u + i, v + i, &t); addedge(u[i], v[i], (bool)t); } T1.dfs(1, 0); S1 = T1.D; T1.dfs(S1, 0); S2 = T1.D; T1.prepare(S1); T2.prepare(S2); } void solve() { int M, t; scanf("%d", &M); while (M--) { scanf("%d", &t); T1.update(u[t], v[t]); T2.update(u[t], v[t]); printf("%d\n", (max(T1.T.mx[0], T2.T.mx[0]))); } } int main() { init(); solve(); return 0; }
#include <bits/stdc++.h> using namespace std; template <typename T> inline T read() { T f = 0, x = 0; char c = getchar(); while (!isdigit(c)) f = c == '-', c = getchar(); while (isdigit(c)) x = x * 10 + c - 48, c = getchar(); return f ? -x : x; } namespace run { const int N = 1e6 + 9, Log = 20; int head[N], nex[N], to[N], cnt = 1, w[N], id[N]; inline void add(int u, int v, int c) { nex[++cnt] = head[u]; head[u] = cnt, to[cnt] = v, w[cnt] = c; } int log[N], dep[N], f[Log][N], dfn[N], dwn[N], num, top, fs[N], sum[N], rak[N]; inline void dfs(int u, int _f) { f[0][++top] = u, fs[u] = top, dep[u] = dep[_f] + 1, rak[dfn[u] = ++num] = u; for (int i = head[u]; i; i = nex[i]) if (to[i] ^ _f) sum[to[i]] = sum[u] ^ w[i], id[i >> 1] = to[i], dfs(to[i], u), f[0][++top] = u; dwn[u] = num; } inline int _min(int u, int v) { return dep[u] < dep[v] ? u : v; } inline void pre() { log[0] = -1; for (int i = 1; i <= top; i++) log[i] = log[i >> 1] + 1; for (int i = 1; i < Log; i++) for (int j = 1; j + (1 << (i - 1)) <= top; j++) f[i][j] = _min(f[i - 1][j], f[i - 1][j + (1 << (i - 1))]); } inline int lca(int u, int v) { int l = min(fs[u], fs[v]), r = max(fs[u], fs[v]), k = log[r - l + 1]; return _min(f[k][l], f[k][r - (1 << k) + 1]); } inline int dist(int u, int v) { if (!u && !v) return -2 * N; if (!u || !v) return -N; return dep[u] + dep[v] - 2 * dep[lca(u, v)]; } namespace Seg { struct lend { int u, v, d; explicit lend() {} lend(int _u, int _v) : u(_u), v(_v) { d = dist(u, v); } }; inline lend merge(lend x, lend y) { lend ret = x; int u1 = x.u, v1 = x.v, u2 = y.u, v2 = y.v; if (lend(u1, u2).d >= ret.d) ret = lend(u1, u2); if (lend(u1, v2).d >= ret.d) ret = lend(u1, v2); if (lend(v1, u2).d >= ret.d) ret = lend(v1, u2); if (lend(v1, v2).d >= ret.d) ret = lend(v1, v2); if (y.d >= ret.d) ret = y; return ret; } int rev[N << 2]; lend l0[N << 2], l1[N << 2]; inline void pushr(int k) { swap(l0[k], l1[k]), rev[k] ^= 1; } inline void pushdown(int k) { if (rev[k]) pushr((k << 1)), pushr((k << 1 | 1)), rev[k] = 0; } inline void pushup(int k) { l0[k] = merge(l0[(k << 1)], l0[(k << 1 | 1)]), l1[k] = merge(l1[(k << 1)], l1[(k << 1 | 1)]); } inline void build(int k, int l, int r) { if (l == r) { l0[k] = l1[k] = lend(0, 0); if (sum[rak[l]]) l1[k] = lend(rak[l], rak[l]); else l0[k] = lend(rak[l], rak[l]); return; } build((k << 1), l, ((l + r) >> 1)), build((k << 1 | 1), ((l + r) >> 1) + 1, r); pushup(k); } inline void modify(int k, int l, int r, int _l, int _r) { if (_l <= l && r <= _r) return pushr(k); pushdown(k); if (_l <= ((l + r) >> 1)) modify((k << 1), l, ((l + r) >> 1), _l, _r); if (_r > ((l + r) >> 1)) modify((k << 1 | 1), ((l + r) >> 1) + 1, r, _l, _r); pushup(k); } inline void check(int k, int l, int r) { cout << l << " " << r << ":----------" << endl; cout << "l0:" << " " << l0[k].u << " " << l0[k].v << " "; cout << "l1:" << " " << l1[k].u << " " << l1[k].v << endl; if (l == r) return; pushdown(k); check((k << 1), l, ((l + r) >> 1)), check((k << 1 | 1), ((l + r) >> 1) + 1, r); } } // namespace Seg int n, m; int main() { n = read<int>(); for (int i = 1; i < n; i++) { int u = read<int>(), v = read<int>(), p = read<int>(); add(u, v, p), add(v, u, p); } dfs(1, 0), pre(), Seg::build(1, 1, n); m = read<int>(); for (int i = 1; i <= m; i++) { int u = id[read<int>()]; Seg::modify(1, 1, n, dfn[u], dwn[u]); printf("%d\n", max(Seg::l0[1].d, Seg::l1[1].d)); } return 0; } } // namespace run int main() { return run::main(); }
#include <bits/stdc++.h> using namespace std; const int MAXN = 500010; vector<pair<pair<int, int>, int>> edge; vector<pair<int, int>> graph[MAXN]; int n, m; int depth[MAXN], ap, bp; class SegmentTree { public: SegmentTree() { cnt = 0; } int dfsArr[MAXN]; int l[MAXN], r[MAXN], f[MAXN], cnt; int te[MAXN * 4], to[MAXN * 4]; int evenLen[MAXN], oddLen[MAXN]; int lazy[MAXN * 4]; void build(int p, int curLen, int val, int pop) { if (curLen % 2 == 0) { this->evenLen[p] = val; this->oddLen[p] = 0; } else { this->oddLen[p] = val; this->evenLen[p] = 0; } l[p] = ++cnt; dfsArr[cnt] = p; for (auto i : graph[p]) { if (i.first == pop) continue; f[i.first] = p; build(i.first, curLen + i.second, val + 1, p); } r[p] = cnt; } void init(int l, int r, int cur) { if (l == r) { te[cur] = evenLen[dfsArr[l]]; to[cur] = oddLen[dfsArr[l]]; return; } int mid = (l + r) / 2; init(l, mid, cur * 2); init(mid + 1, r, cur * 2 + 1); te[cur] = max(te[cur * 2], te[cur * 2 + 1]); to[cur] = max(to[cur * 2], to[cur * 2 + 1]); } void pushdown(int cur, int l, int r) { if (l != r) { lazy[cur * 2] += lazy[cur]; lazy[cur * 2 + 1] += lazy[cur]; if (lazy[cur] % 2 == 1) { swap(te[cur * 2], to[cur * 2]); swap(te[cur * 2 + 1], to[cur * 2 + 1]); } } lazy[cur] = 0; } void change(int l, int r, int tl, int tr, int cur) { if (l > tr || r < tl) return; pushdown(cur, l, r); if (l >= tl && r <= tr) { lazy[cur]++; swap(te[cur], to[cur]); } else { int mid = (l + r) / 2; change(l, mid, tl, tr, cur * 2); change(mid + 1, r, tl, tr, cur * 2 + 1); te[cur] = max(te[cur * 2], te[cur * 2 + 1]); to[cur] = max(to[cur * 2], to[cur * 2 + 1]); } } } t1, t2; void dfs(int x, int f) { for (auto i : graph[x]) { if (i.first == f) continue; depth[i.first] = depth[x] + 1; dfs(i.first, x); } } void GetDiameter() { depth[1] = 0; dfs(1, -1); int len = -1; for (int i = 1; i <= n; i++) { if (depth[i] > len) { ap = i; len = depth[i]; } } depth[1] = 0; dfs(ap, -1); len = -1; for (int i = 1; i <= n; i++) { if (depth[i] > len) { bp = i; len = depth[i]; } } } void DEBUG(int l, int r, int cur) { printf("[%d, %d], lazy: %d even: %d odd: %d\n", l, r, t2.lazy[cur], t2.te[cur], t2.to[cur]); if (l == r) return; int mid = (l + r) / 2; DEBUG(l, mid, cur * 2); DEBUG(mid + 1, r, cur * 2 + 1); } int main() { ios::sync_with_stdio(false); cin >> n; for (int i = 1; i < n; i++) { int u, v, w; cin >> u >> v >> w; edge.push_back(make_pair(make_pair(u, v), w)); graph[u].push_back(make_pair(v, w)); graph[v].push_back(make_pair(u, w)); } GetDiameter(); t1.build(ap, 0, 0, -1); t2.build(bp, 0, 0, -1); t1.f[ap] = -1; t2.f[bp] = -1; t1.init(1, n, 1); t2.init(1, n, 1); cin >> m; for (int i = 1; i <= m; i++) { int x; cin >> x; int node = t1.f[edge[x - 1].first.first] == edge[x - 1].first.second ? edge[x - 1].first.first : edge[x - 1].first.second; t1.change(1, n, t1.l[node], t1.r[node], 1); node = t2.f[edge[x - 1].first.first] == edge[x - 1].first.second ? edge[x - 1].first.first : edge[x - 1].first.second; t2.change(1, n, t2.l[node], t2.r[node], 1); int ans = max(t1.te[1], t2.te[1]); cout << ans << endl; } return 0; }
#include <bits/stdc++.h> using namespace std; struct aaa { int x, y, op; } a[500010]; int ans, cnt, n, tx, ty, tot, mx, e[1000010], nt[1000010], hd[1000010], dep[500010], ru[500010], chu[500010], id[500010], f[2000010][2][2], val[1000010], d[500010], jl[500010][2], lz[2000010]; void build(int x, int y, int w) { tot++; e[tot] = y; val[tot] = w; nt[tot] = hd[x]; hd[x] = tot; } void get(int x, int fa) { int i; dep[x] = dep[fa] + 1; if (dep[x] > dep[mx]) mx = x; for (i = hd[x]; i; i = nt[i]) { if (e[i] == fa) continue; get(e[i], x); } } void dfs(int x, int fa) { int i; ru[x] = ++cnt; id[cnt] = x; dep[x] = dep[fa] + 1; for (i = hd[x]; i; i = nt[i]) { if (e[i] == fa) continue; d[e[i]] = d[x] ^ val[i]; dfs(e[i], x); } chu[x] = cnt; } void pushup(int x) { int i, j; for (i = 0; i < 2; i++) for (j = 0; j < 2; j++) f[x][i][j] = max(f[x * 2][i][j], f[x * 2 + 1][i][j]); } void build1(int x, int l, int r) { if (l == r) { if (d[id[l]] == 0) { f[x][0][0] = jl[id[l]][0]; f[x][1][0] = jl[id[l]][1]; } else { f[x][0][1] = jl[id[l]][0]; f[x][1][1] = jl[id[l]][1]; } return; } int mid = (l + r) / 2; build1(x * 2, l, mid); build1(x * 2 + 1, mid + 1, r); pushup(x); } void pushdown(int x) { if (lz[x]) { lz[x * 2] ^= 1; lz[x * 2 + 1] ^= 1; lz[x] = 0; swap(f[x * 2][0][0], f[x * 2][0][1]); swap(f[x * 2][1][0], f[x * 2][1][1]); swap(f[x * 2 + 1][0][0], f[x * 2 + 1][0][1]); swap(f[x * 2 + 1][1][0], f[x * 2 + 1][1][1]); } } void xiu(int x, int l, int r, int t, int k) { if (l == t && r == k) { lz[x] ^= 1; swap(f[x][0][0], f[x][0][1]); swap(f[x][1][0], f[x][1][1]); return; } pushdown(x); int mid = (l + r) / 2; if (mid >= k) xiu(x * 2, l, mid, t, k); else if (t > mid) xiu(x * 2 + 1, mid + 1, r, t, k); else xiu(x * 2, l, mid, t, mid), xiu(x * 2 + 1, mid + 1, r, mid + 1, k); pushup(x); } int get(int x, int l, int r, int t) { if (l == r) { return d[id[l]] ^ lz[x]; } pushdown(x); int mid = (l + r) / 2; if (mid >= t) return get(x * 2, l, mid, t); else return get(x * 2 + 1, mid + 1, r, t); } int main() { int t1, i, op0, op1; scanf("%d", &n); for (i = 1; i < n; i++) { scanf("%d%d%d", &a[i].x, &a[i].y, &a[i].op); build(a[i].x, a[i].y, a[i].op); build(a[i].y, a[i].x, a[i].op); } get(1, 0); tx = mx; mx = 0; get(tx, 0); for (i = 1; i <= n; i++) jl[i][0] = dep[i] - 1; ty = mx; get(ty, 0); for (i = 1; i <= n; i++) jl[i][1] = dep[i] - 1; dfs(1, 0); build1(1, 1, n); scanf("%d", &t1); while (t1--) { scanf("%d", &i); if (dep[a[i].x] < dep[a[i].y]) swap(a[i].x, a[i].y); xiu(1, 1, n, ru[a[i].x], chu[a[i].x]); op0 = get(1, 1, n, ru[tx]); op1 = get(1, 1, n, ru[ty]); ans = 0; if (op0 == 0) ans = max(ans, f[1][0][0]); else ans = max(ans, f[1][0][1]); if (op1 == 0) ans = max(ans, f[1][1][0]); else ans = max(ans, f[1][1][1]); printf("%d\n", ans); } }
#include <bits/stdc++.h> using namespace std; struct Edge { int to; int tp; int index; }; int timer = 0; vector<vector<Edge> > gr; vector<pair<int, int> > seg; vector<int> tin; vector<int> val; vector<int> euler; void dfs(int vertex, int last, int W) { tin[vertex] = timer++; val[vertex] = W; euler.push_back(vertex); for (auto ed : gr[vertex]) { if (ed.to == last) continue; int index = ed.index; seg[index].first = timer; dfs(ed.to, vertex, W ^ ed.tp); seg[index].second = timer - 1; } } int mx = -1; int opt; void dfs2(int vertex, int last, int d) { if (d > mx) { mx = d; opt = vertex; } for (auto ed : gr[vertex]) { int to = ed.to; if (to == last) continue; dfs2(to, vertex, d + 1); } } pair<int, int> find_diameter() { dfs2(0, -1, 0); int kek = opt; mx = -1; dfs2(kek, -1, 0); return make_pair(kek, opt); } int n; vector<int> dist; void dfs3(int vertex, int last, int d) { dist[vertex] = d; for (auto ed : gr[vertex]) { int to = ed.to; if (to == last) continue; dfs3(to, vertex, d + 1); } } struct Vertex { int max[2]; bool need_push; }; vector<Vertex> rmq; void build(int i, int l, int r) { if (r - l == 1) { int W = euler[l]; rmq[i].need_push = false; rmq[i].max[val[W]] = dist[W]; rmq[i].max[1 - val[W]] = -1; return; } int mid = (l + r) / 2; build(2 * i + 1, l, mid); build(2 * i + 2, mid, r); rmq[i].need_push = false; for (int j = 0; j < 2; ++j) { rmq[i].max[j] = max(rmq[2 * i + 1].max[j], rmq[2 * i + 2].max[j]); } } void push(int i, int l, int r) { if (r - l <= 1) return; if (!rmq[i].need_push) return; rmq[i].need_push = false; for (int j = 2 * i + 1; j <= 2 * i + 2; ++j) { rmq[j].need_push ^= 1; swap(rmq[j].max[0], rmq[j].max[1]); } } void upd(int i, int l, int r, int l1, int r1) { push(i, l, r); if (l1 >= r1) return; if (l == l1 && r == r1) { swap(rmq[i].max[0], rmq[i].max[1]); rmq[i].need_push = true; return; } int mid = (l + r) / 2; upd(2 * i + 1, l, mid, l1, min(r1, mid)); upd(2 * i + 2, mid, r, max(l1, mid), r1); for (int j = 0; j < 2; ++j) { rmq[i].max[j] = max(rmq[2 * i + 1].max[j], rmq[2 * i + 2].max[j]); } } int get_val(int i, int l, int r, int index) { push(i, l, r); if (r - l == 1) { if (rmq[i].max[0] == -1) return 1; return 0; } int mid = (l + r) / 2; if (index < mid) return get_val(2 * i + 1, l, mid, index); return get_val(2 * i + 2, mid, r, index); } vector<int> solve(int vertex, vector<int> queries) { vector<int> ans; dist.assign(n, -1); dfs3(vertex, -1, 0); rmq.assign(4 * n, {}); build(0, 0, n); for (auto first : queries) { upd(0, 0, n, seg[first].first, seg[first].second + 1); int T = get_val(0, 0, n, tin[vertex]); ans.push_back(rmq[0].max[T]); } return ans; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; gr.assign(n, {}); for (int i = 0; i < n - 1; ++i) { int u, v, w; cin >> u >> v >> w; u--, v--; gr[u].push_back({v, w, i}); gr[v].push_back({u, w, i}); } seg.assign(n - 1, make_pair(-1, -1)); tin.assign(n, -1); val.assign(n, -1); dfs(0, -1, 0); pair<int, int> p = find_diameter(); vector<int> queries; int q; cin >> q; for (int i = 0; i < q; ++i) { int first; cin >> first; first--; queries.push_back(first); } auto a = solve(p.first, queries); auto b = solve(p.second, queries); for (int i = 0; i < q; ++i) cout << max(a[i], b[i]) << '\n'; }
#include <bits/stdc++.h> using ll = long long; using ld = long double; using namespace std; const int T = 1 << 20; int mx[T + T][2], flag[T + T]; void combine(int v) { for (int i = 0; i <= 1; ++i) mx[v][i] = max(mx[2 * v][i], mx[2 * v + 1][i]); } void change(int v) { flag[v] ^= 1; swap(mx[v][0], mx[v][1]); } void push(int v) { if (!flag[v]) return; for (auto u : {2 * v, 2 * v + 1}) change(u); flag[v] = 0; } void modify(int x, int y, int v = 1, int l = 0, int r = T - 1) { if (y < l || r < x) return; if (x <= l && r <= y) { change(v); return; } push(v); int m = l + r >> 1; modify(x, y, 2 * v, l, m); modify(x, y, 2 * v + 1, m + 1, r); combine(v); } const int N = 5e5 + 500; int n, a, b, c, q, in[N][2], out[N][2], dis[N], parity[N], czas, edge[N][2]; struct gao { int u, w, id; }; vector<gao> G[N]; pair<int, int> e; void dfs(int v, int p) { dis[v] = dis[p] + 1; e = max(e, {dis[v], v}); for (auto it : G[v]) { int u = it.u; if (u != p) dfs(u, v); } } void dfs2(int v, int p, int type) { in[v][type] = ++czas; for (auto it : G[v]) { int u = it.u; if (u != p) { parity[u] = parity[v] ^ it.w; edge[it.id][type] = u; dfs2(u, v, type); } } out[v][type] = czas; } int main() { scanf("%d", &n); for (int i = 1; i <= n - 1; ++i) { scanf("%d%d%d", &a, &b, &c); G[a].push_back({b, c, i}); G[b].push_back({a, c, i}); } dfs(1, 0); int end[2]; end[0] = e.second; e = {0, 0}; dfs(end[0], 0); end[1] = e.second; for (int j = 0; j <= 1; ++j) { for (int i = 1; i <= n; ++i) parity[i] = 0; dfs(end[j], 0); dfs2(end[j], 0, j); for (int i = 1; i <= n; ++i) mx[in[i][j] + T][parity[i] % 2] = dis[i]; } for (int i = T - 1; 1 <= i; --i) combine(i); scanf("%d", &q); while (q--) { scanf("%d", &a); for (int i = 0; i <= 1; ++i) modify(in[edge[a][i]][i], out[edge[a][i]][i]); printf("%d\n", mx[1][0] - 1); } return 0; }
#include <bits/stdc++.h> using namespace std; struct edge { int u, v, t; } e[500005]; int n, dep0[500005]; vector<pair<int, int> > g[500005]; inline void getrt(int x, int f) { for (int i = 0; i < g[x].size(); i++) { int y = g[x][i].first; if (y == f) continue; dep0[y] = dep0[x] + 1; getrt(y, x); } } struct tree { struct node { int l, r, mx[2], lz; } s[500005 << 2]; inline void build(int k, int l, int r) { s[k].l = l; s[k].r = r; if (l == r) return; int mid = (l + r) >> 1; build(k << 1, l, mid); build(k << 1 | 1, mid + 1, r); } inline void update(int k, int x, int v, int y) { if (s[k].l == s[k].r) { s[k].mx[v & 1] = y; return; } int mid = (s[k].l + s[k].r) >> 1; if (x <= mid) update(k << 1, x, v, y); else update(k << 1 | 1, x, v, y); s[k].mx[0] = max(s[k << 1].mx[0], s[k << 1 | 1].mx[0]); s[k].mx[1] = max(s[k << 1].mx[1], s[k << 1 | 1].mx[1]); } inline void pushdown(int k) { if (s[k].lz) { swap(s[k << 1].mx[0], s[k << 1].mx[1]); swap(s[k << 1 | 1].mx[0], s[k << 1 | 1].mx[1]); } s[k << 1].lz ^= s[k].lz; s[k << 1 | 1].lz ^= s[k].lz; s[k].lz = 0; } inline void add(int k, int l, int r) { if (l <= s[k].l && s[k].r <= r) { swap(s[k].mx[0], s[k].mx[1]); s[k].lz ^= 1; return; } pushdown(k); int mid = (s[k].l + s[k].r) >> 1; if (r <= mid) add(k << 1, l, r); else if (l > mid) add(k << 1 | 1, l, r); else add(k << 1, l, mid), add(k << 1 | 1, mid + 1, r); s[k].mx[0] = max(s[k << 1].mx[0], s[k << 1 | 1].mx[0]); s[k].mx[1] = max(s[k << 1].mx[1], s[k << 1 | 1].mx[1]); } }; struct qaqwq { private: tree st; int L[500005], R[500005], rid[500005], tim = 0, cnt[500005], dep[500005]; public: inline void dfs(int x, int f) { L[x] = ++tim; rid[tim] = x; for (int i = 0; i < g[x].size(); i++) { int y = g[x][i].first, z = g[x][i].second; if (y == f) continue; dep[y] = dep[x] + 1; cnt[y] = cnt[x] + z; dfs(y, x); } R[x] = tim; } inline void init(int rt) { st.build(1, 1, n); dfs(rt, 0); for (int i = 1; i <= n; i++) st.update(1, L[i], cnt[i], dep[i]); } inline void perform(int u, int v) { if (dep[u] > dep[v]) swap(u, v); st.add(1, L[v], R[v]); } inline int query() { return st.s[1].mx[0]; } } p1, p2; int main() { scanf("%d", &n); for (int i = 1; i < n; i++) { int u, v, t; scanf("%d%d%d", &u, &v, &t); e[i] = {u, v, t}; g[u].push_back(make_pair(v, t)); g[v].push_back(make_pair(u, t)); } getrt(1, 0); int s1 = 1, s2 = 1, mx = 0; for (int i = 1; i <= n; i++) if (dep0[i] > mx) mx = dep0[i], s1 = i; dep0[s1] = 0; getrt(s1, 0); mx = 0; for (int i = 1; i <= n; i++) if (dep0[i] > mx) mx = dep0[i], s2 = i; p1.init(s1); p2.init(s2); int m; scanf("%d", &m); while (m--) { int x; scanf("%d", &x); p1.perform(e[x].u, e[x].v); p2.perform(e[x].u, e[x].v); printf("%d\n", max(p1.query(), p2.query())); } return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 500009; vector<pair<int, int>> V[maxn]; int va[maxn], vb[maxn], fa[maxn], ans[maxn], stone[maxn], q[maxn], istone[maxn], tot, dfn[maxn], sz[maxn]; int Max1[maxn << 2], Max2[maxn << 2]; bool lz[maxn << 2]; void build(int rt, int l, int r, int p, int v, int d) { lz[rt] = 0; if (l == r) { if (v & 1) Max2[rt] = d, Max1[rt] = 0; else Max1[rt] = d, Max2[rt] = 0; return; } int mid = (l + r) >> 1; if (p <= mid) build(rt << 1, l, mid, p, v, d); else build(rt << 1 | 1, mid + 1, r, p, v, d); Max1[rt] = max(Max1[rt << 1], Max1[rt << 1 | 1]); Max2[rt] = max(Max2[rt << 1], Max2[rt << 1 | 1]); } void upd(int rt, int l, int r, int ll, int rr) { if (ll <= l && rr >= r) { lz[rt] ^= 1; swap(Max1[rt], Max2[rt]); return; } int mid = (l + r) >> 1; if (lz[rt]) { lz[rt << 1] ^= 1; lz[rt << 1 | 1] ^= 1; swap(Max1[rt << 1], Max2[rt << 1]); swap(Max1[rt << 1 | 1], Max2[rt << 1 | 1]); lz[rt] = 0; } if (ll <= mid) upd(rt << 1, l, mid, ll, rr); if (rr > mid) upd(rt << 1 | 1, mid + 1, r, ll, rr); Max1[rt] = max(Max1[rt << 1], Max1[rt << 1 | 1]); Max2[rt] = max(Max2[rt << 1], Max2[rt << 1 | 1]); } int len, st; int n; void dfs(int u, int f, int d = 0) { if (d >= len) len = d, st = u; for (auto [v, idx] : V[u]) if (v != f) dfs(v, u, d + 1); } void gao(int u, int f, int val = 0, int d = 0) { sz[u] = 1; dfn[u] = ++tot; build(1, 1, n, tot, val, d); for (auto [v, idx] : V[u]) if (v != f) { if (va[idx] == v) fa[idx] = 1; else fa[idx] = 0; gao(v, u, val + stone[idx], d + 1); sz[u] += sz[v]; } } int main() { ios_base::sync_with_stdio(false); cout.tie(0); cin.tie(0); cin >> n; for (int i = 0; i < n - 1; ++i) { cin >> va[i] >> vb[i] >> stone[i]; V[va[i]].emplace_back(vb[i], i); V[vb[i]].emplace_back(va[i], i); } int aq; cin >> aq; for (int i = 0; i < aq; ++i) cin >> q[i], q[i]--; dfs(1, 1); int S = st, T; len = 0; dfs(S, S); T = st; for (int x : {S, T}) { tot = 0; gao(x, x); for (int i = 0; i < aq; ++i) { int op; if (fa[q[i]] == 0) { op = vb[q[i]]; } else { op = va[q[i]]; } upd(1, 1, n, dfn[op], dfn[op] + sz[op] - 1); ans[i] = max(ans[i], Max1[1]); } } for (int i = 0; i < aq; ++i) cout << ans[i] << '\n'; return 0; }
#include <bits/stdc++.h> using namespace std; const int INF = 10000000; pair<int, int> get_diameter(vector<vector<int>> &E) { int N = E.size(); queue<int> Q; Q.push(0); vector<bool> used(N, false); used[0] = true; int s; while (!Q.empty()) { s = Q.front(); Q.pop(); for (int w : E[s]) { if (!used[w]) { used[w] = true; Q.push(w); } } } Q.push(s); vector<bool> used2(N, false); used2[s] = true; int t; while (!Q.empty()) { t = Q.front(); Q.pop(); for (int w : E[t]) { if (!used2[w]) { used2[w] = true; Q.push(w); } } } return make_pair(s, t); } struct lazy_segment_tree { int N; vector<int> ST1, ST2; vector<bool> lazy; lazy_segment_tree() {} lazy_segment_tree(vector<int> &a) { int n = a.size(); N = 1; while (N < n) { N *= 2; } ST1 = vector<int>(N * 2 - 1, 0); for (int i = 0; i < n; i++) { ST1[N - 1 + i] = a[i]; } for (int i = N - 2; i >= 0; i--) { ST1[i] = max(ST1[i * 2 + 1], ST1[i * 2 + 2]); } ST2 = vector<int>(N * 2 - 1, 0); lazy = vector<bool>(N * 2 - 1, false); } void eval(int i) { if (lazy[i]) { if (i < N - 1) { lazy[i * 2 + 1] = !lazy[i * 2 + 1]; lazy[i * 2 + 2] = !lazy[i * 2 + 2]; } swap(ST1[i], ST2[i]); lazy[i] = false; } } void flip(int L, int R, int i, int l, int r) { eval(i); if (r <= L || R <= l) { return; } else if (L <= l && r <= R) { lazy[i] = !lazy[i]; eval(i); } else { int m = (l + r) / 2; flip(L, R, i * 2 + 1, l, m); flip(L, R, i * 2 + 2, m, r); ST1[i] = max(ST1[i * 2 + 1], ST1[i * 2 + 2]); ST2[i] = max(ST2[i * 2 + 1], ST2[i * 2 + 2]); } } void flip(int L, int R) { flip(L, R, 0, 0, N); } int all() { eval(0); return ST1[0]; } }; struct euler_tour { vector<int> in, out, a; lazy_segment_tree ST; void dfs(vector<vector<int>> &E, int v, int dist) { in[v] = a.size(); a.push_back(dist); for (int w : E[v]) { if (in[w] == -1) { dfs(E, w, dist + 1); } } out[v] = a.size(); } euler_tour(vector<vector<int>> &E, int r) { int N = E.size(); in = vector<int>(N, -1); out = vector<int>(N, -1); dfs(E, r, 0); ST = lazy_segment_tree(a); } int dist(int v) { return a[in[v]]; } void flip(int v) { ST.flip(in[v], out[v]); } int query() { return ST.all(); } }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vector<int> u(n - 1), v(n - 1), t(n - 1); for (int i = 0; i < n - 1; i++) { cin >> u[i] >> v[i] >> t[i]; u[i]--; v[i]--; } vector<vector<int>> E(n); for (int i = 0; i < n - 1; i++) { E[u[i]].push_back(v[i]); E[v[i]].push_back(u[i]); } int r1, r2; tie(r1, r2) = get_diameter(E); euler_tour T1(E, r1); euler_tour T2(E, r2); vector<int> c1(n - 1); vector<int> c2(n - 1); for (int i = 0; i < n - 1; i++) { if (T1.dist(u[i]) > T1.dist(v[i])) { c1[i] = u[i]; } else { c1[i] = v[i]; } if (T2.dist(u[i]) > T2.dist(v[i])) { c2[i] = u[i]; } else { c2[i] = v[i]; } } for (int i = 0; i < n - 1; i++) { if (t[i] == 1) { T1.flip(c1[i]); T2.flip(c2[i]); } } int m; cin >> m; for (int i = 0; i < m; i++) { int id; cin >> id; id--; T1.flip(c1[id]); T2.flip(c2[id]); cout << max(T1.query(), T2.query()) << "\n"; } }
#include <bits/stdc++.h> using namespace std; class segtree { public: struct node { int black = INT_MIN; int white = INT_MIN; bool exchange = false; void apply(int l, int r, int v) { if (v >= 0) { int t = v & 1; v >>= 1; (t ? black : white) = v; } else { swap(black, white); exchange ^= true; } } }; node unite(const node &a, const node &b) const { node res; res.black = max(a.black, b.black); res.white = max(a.white, b.white); return res; } inline void push(int x, int l, int r) { int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); if (tree[x].exchange) { tree[x + 1].apply(l, y, -1); tree[z].apply(y + 1, r, -1); tree[x].exchange = false; } } inline void pull(int x, int z) { tree[x] = unite(tree[x + 1], tree[z]); } int n; vector<node> tree; void build(int x, int l, int r) { if (l == r) { return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); build(x + 1, l, y); build(z, y + 1, r); pull(x, z); } template <typename M, typename... T> void build(int x, int l, int r, const vector<M> &v, const T &...t) { if (l == r) { tree[x].apply(l, r, v[l], t...); return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); build(x + 1, l, y, v, t...); build(z, y + 1, r, v, t...); pull(x, z); } template <typename M, typename... T> segtree(const vector<M> &v, const T &...t) { n = v.size(); assert(n > 0); tree.resize(2 * n - 1); build(0, 0, n - 1, v, t...); } segtree(int _n) : n(_n) { assert(n > 0); tree.resize(2 * n - 1); build(0, 0, n - 1); } segtree(){}; node get(int x, int l, int r, int ll, int rr) { if (ll <= l && r <= rr) { return tree[x]; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); push(x, l, r); node res{}; if (rr <= y) { res = get(x + 1, l, y, ll, rr); } else { if (ll > y) { res = get(z, y + 1, r, ll, rr); } else { res = unite(get(x + 1, l, y, ll, rr), get(z, y + 1, r, ll, rr)); } } pull(x, z); return res; } node get(int ll, int rr) { assert(0 <= ll && ll <= rr && rr <= n - 1); return get(0, 0, n - 1, ll, rr); } node get(int p) { assert(0 <= p && p <= n - 1); return get(0, 0, n - 1, p, p); } template <typename... M> void modify(int x, int l, int r, int ll, int rr, const M &...v) { if (ll <= l && r <= rr) { tree[x].apply(l, r, v...); return; } int y = (l + r) >> 1; int z = x + ((y - l + 1) << 1); push(x, l, r); if (ll <= y) { modify(x + 1, l, y, ll, rr, v...); } if (rr > y) { modify(z, y + 1, r, ll, rr, v...); } pull(x, z); } template <typename... M> void modify(int ll, int rr, const M &...v) { assert(0 <= ll && ll <= rr && rr <= n - 1); modify(0, 0, n - 1, ll, rr, v...); } }; int n; int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n; vector<vector<int>> g(n); vector<int> from(n - 1); vector<int> to(n - 1); vector<int> d(n - 1); for (int i = 0; i < n - 1; i++) { int u, v, t; cin >> u >> v >> t; u--; v--; g[u].push_back(i); g[v].push_back(i); from[i] = u; to[i] = v; d[i] = t; } vector<int> dep(n); function<void(int, int)> dfs0 = [&](int v, int p) { if (~p) dep[v] = dep[p] + 1; else dep[v] = 0; for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs0(id, v); } }; dfs0(0, -1); int left_root = max_element(dep.begin(), dep.end()) - dep.begin(); dfs0(left_root, -1); int right_root = max_element(dep.begin(), dep.end()) - dep.begin(); vector<int> order; vector<int> din(n); vector<int> dout(n); vector<int> par(n); function<void(int, int)> dfs = [&](int v, int p) { par[v] = p; if (~p) dep[v] = dep[p] + 1; else dep[v] = 0; din[v] = order.size(); order.push_back(v); for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs(id, v); } dout[v] = order.size() - 1; }; vector<int> R_order, R_in, R_out, R_dep, R_par, L_order, L_in, L_out, L_dep, L_par; dfs(right_root, -1); R_order = order; R_in = din; R_out = dout; R_dep = dep; R_par = par; order.clear(); dfs(left_root, -1); L_order = order; L_in = din; L_out = dout; L_dep = dep; L_par = par; vector<int> pos(n); function<void(int, int, int)> dfs1 = [&](int v, int p, int t) { pos[v] = t; for (int i : g[v]) { int id = from[i] ^ to[i] ^ v; if (id == p) continue; dfs1(id, v, t ^ d[i]); } }; dfs1(0, -1, 0); for (int i = 0; i < n; i++) { L_dep[i] = L_dep[i] * 2 + pos[i]; R_dep[i] = R_dep[i] * 2 + pos[i]; } for (int i = 0; i < n; i++) { L_order[i] = L_dep[L_order[i]]; R_order[i] = R_dep[R_order[i]]; } segtree Lst(L_order); segtree Rst(R_order); int q; cin >> q; while (q--) { int id; cin >> id; id--; int u = from[id]; int v = to[id]; int ret = 0; { if (L_par[v] == u) swap(u, v); Lst.modify(L_in[u], L_out[u], -1); segtree::node x = Lst.get(L_in[left_root], L_out[left_root]); segtree::node y = Lst.get(L_in[left_root], L_in[left_root]); int v = (y.black > INT_MIN ? x.black : x.white); ret = max(ret, v); } { if (R_par[v] == u) swap(u, v); Rst.modify(R_in[u], R_out[u], -1); segtree::node x = Rst.get(R_in[right_root], R_out[right_root]); segtree::node y = Rst.get(R_in[right_root], R_in[right_root]); int v = (y.black > INT_MIN ? x.black : x.white); ret = max(ret, v); } cout << ret << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; inline int read() { char c = getchar(); int x = 0; bool f = 0; for (; !isdigit(c); c = getchar()) f ^= !(c ^ 45); for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48); if (f) x = -x; return x; } int n, m; struct edge { int to, nxt, w; } e[1000005 << 1]; int tot = 1, head[1000005]; inline void adde(int u, int v, int w) { e[++tot] = (edge){v, head[u], w}; head[u] = tot; } int rt, dis[1000005]; void dfs(int u, int pa) { for (int i = head[u]; i; i = e[i].nxt) { int v = e[i].to; if (v == pa) continue; dis[v] = dis[u] + 1, dfs(v, u); } } int find(int xx = 1) { dfs(xx, 0); int u = 1; for (register int i = (1); i <= (n); ++i) if (dis[i] > dis[u]) u = i; return dis[u] = 0, dfs(u, 0), u; } int dfn[1000005], ed[1000005], que[1000005], w[1000005], idx; void getdfn(int u, int pa) { dfn[u] = ++idx; que[idx] = u; for (int i = head[u]; i; i = e[i].nxt) { int v = e[i].to; if (v == pa) continue; w[v] = w[u] ^ e[i].w, getdfn(v, u); } ed[u] = idx; } int cnt, val[1000005 << 4], ls[1000005 << 4], rs[1000005 << 4], rt0, rt1; inline void pushup(int p) { val[p] = max(val[ls[p]], val[rs[p]]); } void build(int& p, int l, int r, bool fg) { p = ++cnt; if (l == r) { if (fg == w[que[l]]) val[p] = dis[que[l]]; return; } int mid = l + r >> 1; build(ls[p], l, mid, fg), build(rs[p], mid + 1, r, fg); pushup(p); } bool in(int l, int r, int ll, int rr) { return ll >= l && rr <= r; } void mdf(int u, int v, int l, int r, int nl, int nr) { int mid = l + r >> 1; if (nl <= mid) { if (in(nl, nr, l, mid)) swap(ls[u], ls[v]); else mdf(ls[u], ls[v], l, mid, nl, nr); } if (nr > mid) { if (in(nl, nr, mid + 1, r)) swap(rs[u], rs[v]); else mdf(rs[u], rs[v], mid + 1, r, nl, nr); } pushup(u), pushup(v); } void out(int p, int l, int r) { if (l == r) { cout << val[p] << ' '; return; } int mid = l + r >> 1; out(ls[p], l, mid), out(rs[p], mid + 1, r); } int res[1000005]; int idid[1000005]; void work(int rt) { w[rt] = 0; getdfn(rt, 0); for (register int i = (1); i <= (cnt); ++i) ls[i] = rs[i] = val[i] = 0; cnt = 0; build(rt0, 1, n, 0), build(rt1, 1, n, 1); for (register int _ = (1); _ <= (m); ++_) { int id = idid[_]; int u = e[id << 1].to, v = e[id << 1 | 1].to; if (dfn[u] < dfn[v]) swap(u, v); mdf(rt0, rt1, 1, n, dfn[u], ed[u]); res[_] = max(res[_], val[rt0]); } } signed main() { n = read(); for (register int i = (2); i <= (n); ++i) { int u = read(), v = read(), w = read(); adde(u, v, w), adde(v, u, w); } m = read(); for (register int i = (1); i <= (m); ++i) idid[i] = read(); rt = find(); work(rt); rt = find(rt); idx = 0, w[rt] = 0; work(rt); for (register int i = (1); i <= (m); ++i) cout << res[i] << endl; return 0; }
#include <bits/stdc++.h> const int MAXN = 5e5; int n, m, root, tim, edge; int U[MAXN | 1], V[MAXN | 1], W[MAXN | 1], dfn[MAXN | 1], size[MAXN | 1], xorv[MAXN | 1], ID[MAXN | 1], depth[MAXN | 1], fst[MAXN | 1], ans[MAXN | 1]; std::vector<int> que; struct Edge { int to, w, nxt; Edge(int _to = 0, int _w = 0, int _nxt = 0) : to(_to), w(_w), nxt(_nxt) {} } e[MAXN << 1]; inline int read() { register int x = 0, v = 1; register char ch = getchar(); while (!isdigit(ch)) { if (ch == '-') v = -1; ch = getchar(); } while (isdigit(ch)) { x = x * 10 + ch - '0'; ch = getchar(); } return x * v; } inline void add_edge(int a, int b, int c) { e[++edge] = Edge(b, c, fst[a]); fst[a] = edge; } int BFS(int x) { int ans = 1; bool vis[MAXN | 1]; std::queue<int> q; memset(vis, 0, sizeof(vis)); q.push(x); vis[x] = 1; do { int from = q.front(); q.pop(); ans = from; for (int k = fst[from]; k; k = e[k].nxt) { int to = e[k].to; if (vis[to]) continue; vis[to] = 1; q.push(to); } } while (!q.empty()); return ans; } void dfs(int x, int fa) { ID[dfn[x] = ++tim] = x; size[x] = 1; depth[x] = depth[fa] + 1; for (int k = fst[x]; k; k = e[k].nxt) { int to = e[k].to, w = e[k].w; if (to == fa) continue; xorv[to] = xorv[x] ^ w; dfs(to, x); size[x] += size[to]; } } namespace SegmentTree { int max0[MAXN << 2 | 1], max1[MAXN << 2 | 1], tag[MAXN << 2 | 1]; void push_up(int o) { max0[o] = std::max(max0[o << 1], max0[o << 1 | 1]); max1[o] = std::max(max1[o << 1], max1[o << 1 | 1]); } void push_down(int o) { if (!tag[o]) return; std::swap(max0[o << 1], max1[o << 1]); std::swap(max0[o << 1 | 1], max1[o << 1 | 1]); tag[o << 1] ^= 1; tag[o << 1 | 1] ^= 1; tag[o] = 0; } void build(int o, int l, int r) { tag[o] = 0; max0[o] = max1[o] = 0; if (l == r) { if (xorv[ID[l]]) max1[o] = depth[ID[l]]; else max0[o] = depth[ID[l]]; return; } int mid = (l + r) >> 1; build(o << 1, l, mid); build(o << 1 | 1, mid + 1, r); push_up(o); } void flip(int o, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) { std::swap(max0[o], max1[o]); tag[o] ^= 1; return; } int mid = (l + r) >> 1; push_down(o); if (ql <= mid) flip(o << 1, l, mid, ql, qr); if (mid < qr) flip(o << 1 | 1, mid + 1, r, ql, qr); push_up(o); } int query(int o, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) return max1[o]; int mid = (l + r) >> 1, res = 0; push_down(o); if (ql <= mid) res = query(o << 1, l, mid, ql, qr); if (mid < qr) res = std::max(res, query(o << 1 | 1, mid + 1, r, ql, qr)); return res; } } // namespace SegmentTree using namespace SegmentTree; int main() { n = read(); for (int i = 1; i < n; ++i) { U[i] = read(); V[i] = read(); W[i] = read(); add_edge(U[i], V[i], W[i]); add_edge(V[i], U[i], W[i]); } root = BFS(1); int lst = root; dfs(root, 0); build(1, 1, n); m = read(); for (int i = 1; i <= m; ++i) { int x = read(), u = U[x], v = V[x]; que.push_back(x); if (depth[u] < depth[v]) std::swap(u, v); flip(1, 1, n, dfn[u], dfn[u] + size[u] - 1); ans[i] = max0[1] - 1; } root = BFS(root); xorv[root] = 0; tim = 0; dfs(root, 0); build(1, 1, n); for (int i = 1; i <= m; ++i) { int x = que[i - 1], u = U[x], v = V[x]; if (depth[u] < depth[v]) std::swap(u, v); flip(1, 1, n, dfn[u], dfn[u] + size[u] - 1); ans[i] = std::max(max0[1] - 1, ans[i]); } for (int i = 1; i <= m; ++i) printf("%d\n", ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; struct node { int to, next, w; } e[1011000]; int tot, h[500100], n, rt1, rt2, dep[501000], U[501000], V[500100], W[500100]; inline void DFS(int now, int ffa) { dep[now] = dep[ffa] + 1; for (register int i = h[now]; i; i = e[i].next) { int to = e[i].to; if (to == ffa) continue; DFS(to, now); } } inline void add(int from, int to, int w) { e[++tot].next = h[from]; h[from] = tot; e[tot].to = to; e[tot].w = w; } struct Segment_Tree { int tag[2001000], Max[2001000][2]; inline void Update(int now) { Max[now][0] = max(Max[now << 1][0], Max[now << 1 | 1][0]); Max[now][1] = max(Max[now << 1][1], Max[now << 1 | 1][1]); } inline void Pushdown(int now) { if (tag[now]) { swap(Max[now << 1][0], Max[now << 1][1]); swap(Max[now << 1 | 1][0], Max[now << 1 | 1][1]); tag[now << 1] ^= 1; tag[now << 1 | 1] ^= 1; tag[now] = 0; } } inline void Modify(int now, int l, int r, int x, int y) { if (x <= l && r <= y) { swap(Max[now][0], Max[now][1]); tag[now] ^= 1; return; } int mid = (l + r) >> 1; Pushdown(now); if (x <= mid) Modify(now << 1, l, mid, x, y); if (y > mid) Modify(now << 1 | 1, mid + 1, r, x, y); Update(now); } }; struct Tree { int rt, depp[500100], fa[501000], Seq[501000], cnt, in[500100], out[501000]; Segment_Tree T; inline void Build(int now, int l, int r) { if (l == r) { T.Max[now][0] = depp[Seq[l]], T.Max[now][1] = T.tag[now] = 0; return; } int mid = (l + r) >> 1; Build(now << 1, l, mid); Build(now << 1 | 1, mid + 1, r); T.Update(now); } inline void Pre_DFS(int now, int ffa) { fa[now] = ffa; Seq[++cnt] = now; in[now] = cnt; for (register int i = h[now]; i; i = e[i].next) { int to = e[i].to; if (to == ffa) continue; depp[to] = depp[now] + 1; Pre_DFS(to, now); } out[now] = cnt; } inline void Buildd() { cnt = 0; Pre_DFS(rt, 0); Build(1, 1, n); for (register int i = 1; i < n; ++i) { if (depp[U[i]] > depp[V[i]]) swap(U[i], V[i]); if (W[i]) T.Modify(1, 1, n, in[V[i]], out[V[i]]); } } } T1, T2; int main() { scanf("%d", &n); for (register int i = 1; i < n; ++i) { int u, v, w; scanf("%d%d%d", &u, &v, &w); add(u, v, w); add(v, u, w); U[i] = u; V[i] = v; W[i] = w; } DFS(1, 0); int Max = 0; for (register int i = 1; i <= n; ++i) if (dep[i] > Max) Max = dep[i], rt1 = i; DFS(rt1, 0); Max = 0; for (register int i = 1; i <= n; ++i) if (dep[i] > Max) Max = dep[i], rt2 = i; T1.rt = rt1, T2.rt = rt2; T1.Buildd(); T2.Buildd(); int m; scanf("%d", &m); for (register int i = 1; i <= m; ++i) { int idx; scanf("%d", &idx); if (T1.depp[U[idx]] > T1.depp[V[idx]]) swap(U[idx], V[idx]); T1.T.Modify(1, 1, n, T1.in[V[idx]], T1.out[V[idx]]); if (T2.depp[U[idx]] > T2.depp[V[idx]]) swap(U[idx], V[idx]); T2.T.Modify(1, 1, n, T2.in[V[idx]], T2.out[V[idx]]); cout << max(T1.T.Max[1][0], T2.T.Max[1][0]) << "\n"; } return 0; }
#include <bits/stdc++.h> #pragma GCC optimize(2) #pragma GCC optimize(3) using namespace std; template <typename T1, typename T2> void ckmin(T1 &a, T2 b) { if (a > b) a = b; } template <typename T1, typename T2> void ckmax(T1 &a, T2 b) { if (a < b) a = b; } template <typename T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; } int read() { int x = 0, f = 0; char ch = getchar(); while (!isdigit(ch)) f |= ch == '-', ch = getchar(); while (isdigit(ch)) x = 10 * x + ch - '0', ch = getchar(); return f ? -x : x; } const int N = 1000005; const int inf = 1e8; struct Edge { int to, nxt, val; } edge[N << 1]; int head[N], tot; void add(int u, int v, int w) { edge[++tot] = {v, head[u], w}, head[u] = tot; } int dfn[N << 1], pos[N], idx; int dep[N], wdep[N], tin[N], tout[N]; void dfs(int u, int fa) { dfn[++idx] = u, tin[u] = idx; for (int i = head[u]; i; i = edge[i].nxt) { int v = edge[i].to; if (v == fa) continue; pos[(i + 1) >> 1] = v; dep[v] = dep[u] + 1; wdep[v] = wdep[u] + edge[i].val; dfs(v, u); dfn[++idx] = u; } tout[u] = idx; } int n; int W[N << 2][2], M[N << 2], LM[N << 2][2], MR[N << 2][2], LMR[N << 2][2]; int lzy[N << 2]; void pushup(int u) { M[u] = max(M[(u << 1)], M[(u << 1 | 1)]); for (int k = 0; k < 2; k++) { W[u][k] = max(W[(u << 1)][k], W[(u << 1 | 1)][k]); LM[u][k] = max(LM[(u << 1)][k], LM[(u << 1 | 1)][k]); MR[u][k] = max(MR[(u << 1)][k], MR[(u << 1 | 1)][k]); LMR[u][k] = max(LMR[(u << 1)][k], LMR[(u << 1 | 1)][k]); LM[u][k] = max(LM[u][k], W[(u << 1)][k] + M[(u << 1 | 1)]); MR[u][k] = max(MR[u][k], M[(u << 1)] + W[(u << 1 | 1)][k]); } for (int k1 = 0; k1 < 2; k1++) { for (int k2 = 0; k2 < 2; k2++) { ckmax(LMR[u][k1 ^ k2], max(LM[(u << 1)][k1] + W[(u << 1 | 1)][k2], W[(u << 1)][k1] + MR[(u << 1 | 1)][k2])); } } } void build(int u, int l, int r) { if (l == r) { int k = wdep[dfn[l]]; if (k % 2 == 0) k = 0; else k = 1; W[u][k] = dep[dfn[l]], M[u] = -2 * dep[dfn[l]]; LM[u][k] = MR[u][k] = -dep[dfn[l]]; W[u][k ^ 1] = -inf, LM[u][k ^ 1] = MR[u][k ^ 1] = -inf; return; } int mid = l + r >> 1; build((u << 1), l, mid), build((u << 1 | 1), mid + 1, r); pushup(u); } void rot(int u) { swap(W[u][0], W[u][1]); swap(LM[u][0], LM[u][1]); swap(MR[u][0], MR[u][1]); lzy[u] ^= 1; } void pushdown(int u) { if (lzy[u]) { rot((u << 1)), rot((u << 1 | 1)); lzy[u] = 0; } } void update(int u, int l, int r, int ql, int qr) { if (ql <= l && r <= qr) { rot(u); return; } int mid = l + r >> 1; pushdown(u); if (ql <= mid) update((u << 1), l, mid, ql, qr); if (qr > mid) update((u << 1 | 1), mid + 1, r, ql, qr); pushup(u); } int main() { scanf("%d", &n); for (int i = 1; i < n; i++) { int u, v, w; scanf("%d%d%d", &u, &v, &w); add(u, v, w), add(v, u, w); } dfs(1, 0); build(1, 1, idx); int q = read(); while (q--) { int d = read(); update(1, 1, idx, tin[pos[d]], tout[pos[d]]); printf("%d\n", LMR[1][0]); } return 0; }
#include <bits/stdc++.h> using namespace std; int n, a, b, d[2], l, comp; int kr[1000010]; int wg[1000010]; int nr[2][500001]; int mx[2][500001]; int gle[2][500001]; int st[2][1048576][3]; vector<int> v[500001]; void push(int x, int y) { if (st[y][x][2]) { int l = x << 1; int r = l + 1; swap(st[y][l][0], st[y][l][1]); swap(st[y][r][0], st[y][r][1]); st[y][l][2] ^= 1; st[y][r][2] ^= 1; st[y][x][2] = 0; } } void update(int x, int y) { st[y][x][0] = max(st[y][x * 2][0], st[y][x * 2 + 1][0]); st[y][x][1] = max(st[y][x * 2][1], st[y][x * 2 + 1][1]); } void ins(int y, int x, int l, int r, int ll, int rr) { if (l > rr || r < ll) { return; } if (ll <= l && r <= rr) { swap(st[y][x][0], st[y][x][1]); st[y][x][2] ^= 1; return; } push(x, y); ins(y, x * 2, l, (l + r) / 2, ll, rr); ins(y, x * 2 + 1, (l + r) / 2 + 1, r, ll, rr); update(x, y); } void dia(int x, int dl, int pop) { if (b < dl) { a = x; b = dl; } for (int i : v[x]) { if (kr[i] != pop) { dia(kr[i], dl + 1, x); } } } void dfs_gle(int x, int y, int par, int pop) { ++l; nr[y][x] = l; st[y][l + comp - 1][par] = gle[y][x]; st[y][l + comp - 1][par ^ 1] = -1e9; for (int i : v[x]) { if (kr[i] != pop) { gle[y][kr[i]] = gle[y][x] + 1; dfs_gle(kr[i], y, par ^ wg[i], x); } } mx[y][x] = l; } int main() { scanf("%d", &n); comp = 1; while (comp < n) { comp <<= 1; } for (int i = 1; i < n; ++i) { scanf("%d%d%d", &a, &b, &wg[i * 2]); kr[i * 2] = a; kr[i * 2 + 1] = b; wg[i * 2 + 1] = wg[i * 2]; v[a].push_back(i * 2 + 1); v[b].push_back(i * 2); } b = -1; dia(1, 0, 0); d[0] = a; b = -1; dia(a, 0, 0); d[1] = a; l = 0; dfs_gle(d[0], 0, 0, 0); l = 0; dfs_gle(d[1], 1, 0, 0); for (int i = comp - 1; i; --i) { update(i, 0); update(i, 1); } int q; scanf("%d", &q); while (q--) { int x; scanf("%d", &x); int ret = 0; a = kr[x * 2]; b = kr[x * 2 + 1]; if (gle[0][a] > gle[0][b]) { swap(a, b); } ins(0, 1, 1, comp, nr[0][b], mx[0][b]); ret = max(ret, st[0][1][0]); if (gle[1][a] > gle[1][b]) { swap(a, b); } ins(1, 1, 1, comp, nr[1][b], mx[1][b]); ret = max(ret, st[1][1][0]); printf("%d\n", ret); } return 0; }