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#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 5; int n; int a[N]; int dp[N][7][2]; bool nss[N]; vector<int> pr[N]; vector<int> g[N]; void init() { for (int i = 2; i < N; i++) { if (!nss[i]) { for (int j = i; j < N; j += i) { nss[j] = 1; pr[j].push_back(i); } } } } int ans; void dfs(int u, int fa) { for (int i = 0; i < pr[a[u]].size(); i++) { dp[u][i][0] = 1; } for (auto v : g[u]) { if (v == fa) continue; dfs(v, u); for (int i = 0; i < pr[a[u]].size(); i++) { int x = pr[a[u]][i]; if (a[v] % x == 0) { int pos = find(pr[a[v]].begin(), pr[a[v]].end(), x) - pr[a[v]].begin(); int tmp = dp[v][pos][0] + 1; if (tmp > dp[u][i][0]) { dp[u][i][1] = dp[u][i][0]; dp[u][i][0] = tmp; } else if (tmp > dp[u][i][1]) { dp[u][i][1] = tmp; } } } } for (int i = 0; i < pr[a[u]].size(); i++) { ans = max(ans, dp[u][i][0]); ans = max(ans, dp[u][i][0] + dp[u][i][1] - 1); } } int main() { init(); scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); } for (int i = 1; i < n; i++) { int a, b; scanf("%d %d", &a, &b); g[a].push_back(b); g[b].push_back(a); } ans = 0; dfs(1, -1); cout << ans; }
#include <bits/stdc++.h> using namespace std; inline int read() { register int x = 0, t = 1; register char ch = getchar(); while ((ch < '0' || ch > '9') && ch != '-') { ch = getchar(); } if (ch == '-') { t = -1, ch = getchar(); } while (ch <= '9' && ch >= '0') { x = x * 10 + ch - 48, ch = getchar(); } return x * t; } struct Line { int v, next; } e[222222 << 1]; int h[222222], cnt = 1, mx; inline void Add(int u, int v) { e[cnt] = (Line){v, h[u]}; h[u] = cnt++; } vector<int> ys[222222]; int n, a[222222], tot; bool book[222222], vis[222222]; long long ans[222222]; void Div(int x, int id) { for (int i = 1, m = sqrt(x); i <= m; ++i) if (x % i == 0) { ys[i].push_back(id); if (i * i != x) { ys[x / i].push_back(id); } } } void dfs(int u, int ff) { if (!book[u]) { return; } vis[u] = true; ++tot; for (int i = h[u]; i; i = e[i].next) if (e[i].v != ff) { dfs(e[i].v, u); } } int main() { n = read(); for (int i = 1; i <= n; ++i) { mx = max(mx, a[i] = read()); } for (int i = 1; i <= n; ++i) { Div(a[i], i); } for (int i = 1; i < n; ++i) { int u = read(), v = read(); Add(u, v); Add(v, u); } for (int i = 1; i <= mx; ++i) { for (int j = 0, l = ys[i].size(); j < l; ++j) { int v = ys[i][j]; vis[v] = false; book[v] = true; } for (int j = 0, l = ys[i].size(); j < l; ++j) { tot = 0; int v = ys[i][j]; if (!vis[v]) { dfs(v, 0); } book[v] = false; ans[i] += 1ll * tot * (tot - 1) / 2 + tot; } } for (int i = mx; i; --i) if (ans[i]) for (int j = i + i; j <= mx; j += i) { ans[i] -= ans[j]; } for (int i = 1; i <= mx; ++i) if (ans[i]) { printf("%d %I64d\n", i, ans[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; const int M = 1000001; int n, m, k, a[M], ver[M], nex[M], head[M], cnt, fa[M], dp[M], tmp[M], sz[M]; vector<int> v[M]; long long d[M]; void add(int x, int y) { ver[++cnt] = y, nex[cnt] = head[x], head[x] = cnt; ver[++cnt] = x, nex[cnt] = head[y], head[y] = cnt; } void dfs(int x, int f) { fa[x] = f; dp[x] = dp[f] + 1; for (int i = head[x]; i; i = nex[i]) { if (ver[i] == f) continue; dfs(ver[i], x); } } bool cmp(int a, int b) { return dp[a] > dp[b]; } int main() { scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%d", &a[i]), v[a[i]].push_back(i), m = max(m, a[i]); for (int i = 1; i < n; i++) { int x, y; scanf("%d%d", &x, &y); add(x, y); } dfs(1, 0); for (int i = 1; i <= m; i++) { int cnt = 0; for (int j = i; j <= m; j += i) { for (int l = 0; l < v[j].size(); l++) tmp[++cnt] = v[j][l]; } sort(tmp + 1, tmp + 1 + cnt, cmp); d[i] = cnt; for (int j = 1; j <= cnt; j++) sz[tmp[j]] = 1; for (int j = 1; j <= cnt; j++) { int x = tmp[j], f = fa[x]; if (!sz[f]) continue; d[i] = (d[i] + (long long)sz[x] * sz[f]); sz[f] += sz[x]; } for (int j = 1; j <= cnt; j++) sz[tmp[j]] = 0; } for (int i = m; i >= 1; i--) for (int j = i + i; j <= m; j += i) d[i] -= d[j]; for (int i = 1; i <= m; i++) if (d[i]) printf("%d %lld\n", i, d[i]); }
#include <bits/stdc++.h> class dsu { int fa[200005], sz[200005]; public: void init(int pos) { fa[pos] = -1; sz[pos] = 1; } int query_root(int pos) { return fa[pos] == -1 ? pos : (fa[pos] = query_root(fa[pos])); } int query_size(int pos) { return sz[query_root(pos)]; } void merge(int pa, int child) { pa = query_root(pa); child = query_root(child); if (pa != child) { fa[child] = pa; sz[pa] += sz[child]; } } }; dsu du; int a[200005], maxa; std::vector<int> nodes[200005]; std::vector<int> adj[200005]; int64_t ans[200005]; int n; int main(int argc, char* argv[]) { scanf("%d", &n); for (int i = 1; i <= n; ++i) { scanf("%d", &a[i]); nodes[a[i]].push_back(i); maxa = std::max(maxa, a[i]); } for (int i = 1; i < n; ++i) { int x, y; scanf("%d%d", &x, &y); adj[x].push_back(y); adj[y].push_back(x); } for (int i = maxa; i > 0; --i) { int64_t& nowans = ans[i]; std::vector<int> rd; for (int j = i; j <= maxa; j += i) { for (int nd : nodes[j]) du.init(nd); rd.insert(rd.end(), nodes[j].begin(), nodes[j].end()); } for (int nd : rd) { for (int nxt : adj[nd]) { if (a[nxt] % i) continue; else { if (du.query_root(nd) != du.query_root(nxt)) { nowans += (int64_t)du.query_size(nd) * du.query_size(nxt); du.merge(nd, nxt); } } } } for (int j = i + i; j <= maxa; j += i) nowans -= ans[j]; } for (int i = 1; i <= maxa; ++i) ans[i] += nodes[i].size(); for (int i = 1; i <= maxa; ++i) { if (ans[i]) printf("%d %lld\n", i, ans[i]); } return 0; }
#include <bits/stdc++.h> int primes[] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443}; int mgcd = 0; int n; std::vector<int> a; std::vector<std::vector<int>> e; int work(int v, int p, int d, bool strict) { if (d < 2) { return 0; } bool ok = a[v] % d == 0; if (ok) { while (a[v] % d == 0) { a[v] /= d; } } if (strict && !ok) { return 0; } int m1 = 0; int m2 = 0; std::vector<int> children = e[v]; for (std::vector<int>::const_iterator i = children.begin(); i != children.end(); ++i) { if (*i != p) { int ch = work(*i, v, d, strict); if (ch > m2) { m1 = m2; m2 = ch; } else if (ch > m1) { m1 = ch; } } } if (ok && m1 + m2 + 1 > mgcd) { mgcd = m1 + m2 + 1; } return ok ? m2 + 1 : 0; } int main() { std::cin >> n; a.resize(n); e.resize(n); for (int i = 0; i < n; ++i) { std::cin >> a[i]; } for (int i = 0; i < n - 1; ++i) { int x, y; std::cin >> x >> y; --x; --y; e[x].push_back(y); e[y].push_back(x); } for (int i = 0; i < sizeof(primes) / sizeof(int); ++i) { int d = primes[i]; work(0, -1, d, false); } for (int i = 0; i < n; ++i) { if (a[i] > 444) { work(i, -1, a[i], true); } } std::cout << mgcd << std::endl; }
#include <bits/stdc++.h> using namespace std; const int maxN = 2e5 + 13, N = 2e5; long long n, ans[maxN], a[maxN], cur; vector<int> adj[maxN], vec[maxN], node, dv[maxN]; bool mark[maxN]; void dfs(int v, int val) { mark[v] = 1; node.push_back(v); if (a[v] % val == 0) cur++; for (auto u : adj[v]) { if (!mark[u] && a[u] % val == 0) dfs(u, val); } } long long solve(int x) { long long ret = 0; for (auto a : vec[x]) { cur = 0; if (!mark[a]) { dfs(a, x); ret += cur * (cur + 1) / 2; } } while (node.size()) { int v = node.back(); node.pop_back(); mark[v] = 0; } return ret; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); cin >> n; for (int i = 1; i <= N; i++) for (int j = 1; j * j <= i; j++) { if (i % j == 0) { dv[i].push_back(j); if (j * j != i) dv[i].push_back(i / j); } } for (int i = 0; i < n; i++) { cin >> a[i + 1]; for (auto j : dv[a[i + 1]]) { vec[j].push_back(i + 1); } } for (int i = 0; i < n - 1; i++) { int u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for (int i = N; i >= 1; i--) { ans[i] += solve(i); for (auto j : dv[i]) { if (j != i) ans[j] -= ans[i]; } } for (int i = 1; i <= N; i++) if (ans[i] != 0) cout << i << " " << ans[i] << '\n'; }
#include <bits/stdc++.h> #pragma GCC optimize("O3") using namespace std; const long double pi = 3.141592653589793238462643383279; const long double log23 = 1.58496250072115618145373894394781; const long double eps = 1e-11; const long long INF = 1e18 + 239; const long long prost = 239; const int two = 2; const int th = 3; const long long MOD = 1e9 + 7; const long long MOD2 = MOD * MOD; const int BIG = 2 * 1e9 + 239; const int alf = 26; const int dx[4] = {-1, 0, 1, 0}; const int dy[4] = {0, 1, 0, -1}; const int dxo[8] = {-1, -1, -1, 0, 1, 1, 1, 0}; const int dyo[8] = {-1, 0, 1, 1, 1, 0, -1, -1}; const int dig = 10; const string str_alf = "abcdefghijklmnopqrstuvwxyz"; const string str_alf_big = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; const int day[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int digarr[10] = {6, 2, 5, 5, 4, 5, 6, 3, 7, 6}; const int bt = 31; template <typename T> inline T gcd(T a, T b) { return a ? gcd(b % a, a) : b; } template <typename T> inline T lcm(T a, T b) { return (a / gcd(a, b)) * b; } inline bool is_down(char x) { return ('a' <= x && x <= 'z'); } inline bool is_upper(char x) { return ('A' <= x && x <= 'Z'); } inline bool is_digit(char x) { return ('0' <= x && x <= '9'); } long long power(long long a, int k) { long long ans = 1; while (k) { if (k & 1) ans = (ans * a) % MOD; ans = (ans * ans) % MOD; k >>= 1; } return ans; } mt19937 rnd(239); const int M = 2 * 1e5 + 239; const int N = 2 * 1e3 + 239; const int L = 20; const int T = (1 << 20); const int B = trunc(sqrt(M)) + 1; const int X = 1e6 + 239; bool can[M], used[M]; int n, a[M]; vector<int> ids[M]; vector<int> v[M]; long long ans[M], sz; inline void dfs(int p) { used[p] = true; sz++; for (int i : v[p]) if (can[i] && !used[i]) dfs(i); } int main() { ios_base::sync_with_stdio(0); cin >> n; for (int i = 0; i < n; i++) cin >> a[i]; for (int i = 0; i < n; i++) ids[a[i]].push_back(i); for (int i = 0; i < n - 1; i++) { int s, f; cin >> s >> f; s--, f--; v[s].push_back(f); v[f].push_back(s); } memset(can, 0, sizeof(can)); memset(used, 0, sizeof(used)); for (int i = 1; i < M; i++) { vector<int> now; for (int x = i; x < M; x += i) for (int t : ids[x]) now.push_back(t); for (int t : now) can[t] = true; ans[i] = 0; for (int t : now) if (!used[t]) { sz = 0; dfs(t); ans[i] += (sz * (sz + 1)) / 2LL; } for (int t : now) can[t] = false; for (int t : now) used[t] = false; } for (int i = M - 1; i >= 1; i--) for (int x = 2 * i; x < M; x += i) ans[i] -= ans[x]; for (int i = 1; i < M; i++) if (ans[i] != 0) cout << i << " " << ans[i] << "\n"; return 0; }
#include <bits/stdc++.h> using namespace std; int prime[50000]; int lp[200102]; class prime_class { public: long top; prime_class() { int i, i2, j; top = 0; lp[0] = 0; lp[1] = 1; for (i = 2; i < 200102; i++) lp[i] = 0; top = 0; for (i = 2; i < 200102; ++i) { if (lp[i] == 0) { lp[i] = i; prime[top++] = i; } for (j = 0; (j < top) && (prime[j] <= lp[i]) && (i * prime[j] < 200102); ++j) lp[i * prime[j]] = prime[j]; } } bool isprime(int key) { if (key < 200102) return (lp[key] == key) && (key >= 2); else { int i; for (i = 0; (i < top) && (prime[i] * prime[i] <= key); i++) if (key % prime[i] == 0) return false; return true; } } unordered_map<int, int> factorize(int key) { unordered_map<int, int> ans; while (lp[key] != key) { ans[lp[key]]++; key /= lp[key]; } if (key > 1) ans[key]++; return ans; } vector<pair<long long, long long>> factorize_full(long long key) { vector<pair<long long, long long>> ans; long i, ct; for (i = 0; (i < top) && (prime[i] <= key); i++) if (key % prime[i] == 0) { ct = 0; while (key % prime[i] == 0) { ct++; key /= prime[i]; } ans.push_back({prime[i], ct}); } if (key > 1) { ans.push_back({key, 1}); } return ans; } void generate_divisors(int step, int v, vector<pair<int, int>> &fp, vector<int> &ans) { if (step < fp.size()) { generate_divisors(step + 1, v, fp, ans); for (int i = 1; i <= fp[step].second; i++) { v *= fp[step].first; generate_divisors(step + 1, v, fp, ans); } } else ans.push_back(v); } vector<int> get_divisors(int key) { unordered_map<int, int> f = factorize(key); int n = f.size(); vector<pair<int, int>> fp; for (auto p : f) fp.push_back(p); vector<int> ans; generate_divisors(0, 1, fp, ans); return ans; } }; int main() { ios::sync_with_stdio(false); cin.tie(0); prime_class pr; int n, i, j, k, x, y, id, ans; cin >> n; vector<int> a(n + 1); for (i = 1; i <= n; i++) cin >> a[i]; vector<vector<int>> adj(n + 1), son(n + 1); vector<int> parent(n + 1, -1); for (i = 1; i <= n - 1; i++) { cin >> x >> y; adj[x].push_back(y); adj[y].push_back(x); } queue<int> q; stack<int> st; q.push(1); parent[1] = 0; st.push(1); while (!q.empty()) { id = q.front(); q.pop(); for (auto p : adj[id]) { if (parent[p] == -1) { parent[p] = id; son[id].push_back(p); q.push(p); st.push(p); } } } ans = 0; vector<map<int, int>> best(n + 1); while (!st.empty()) { id = st.top(); st.pop(); if (a[id] > 1) ans = max(ans, 1); unordered_map<int, int> f = pr.factorize(a[id]); for (auto p : f) best[id][p.first] = 1; for (auto x : son[id]) { for (auto p : best[x]) { if (best[id].find(p.first) != best[id].end()) { ans = max(ans, best[id][p.first] + p.second); best[id][p.first] = max(best[id][p.first], 1 + p.second); } } } } cout << ans << "\n"; return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> inline T bigmod(T p, T e, T M) { long long ret = 1; for (; e > 0; e >>= 1) { if (e & 1) ret = (ret * p) % M; p = (p * p) % M; } return (T)ret; } template <class T> inline T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); } template <class T> inline T lcm(T a, T b) { return (a / gcd(a, b)) * b; } template <class T> inline T modinverse(T a, T M) { return bigmod(a, M - 2, M); } template <class T> inline T bpow(T p, T e) { long long ret = 1; for (; e > 0; e >>= 1) { if (e & 1) ret = (ret * p); p = (p * p); } return (T)ret; } template <class T> inline T gethash(T h[], T power[], int l, int r) { if (r < l) return (T)0; return h[l] - h[r + 1] * power[r - l + 1]; } struct data { data() {} bool friend operator<(data a, data b) { return 0; } }; int n, m, k; long long N, M, K; int a[200005]; long long ans[200005]; vector<int> adj[200005]; int subtree[200005]; bool bad[200005]; int tot = 0; int cnt[200005]; unordered_set<int> st; unordered_set<int>::iterator it; unordered_map<int, int> mm[200005]; int _gcd(int a, int b) { if (a == 0) return b; if (b == 0) return a; int p = _gcd(b, a % b); return p; } void dfs(int u, int p) { subtree[u] = 1; tot++; for (int i = 0; i < adj[u].size(); i++) { int v = adj[u][i]; if (v == p || bad[v]) continue; dfs(v, u); subtree[u] += subtree[v]; } } int getcenter(int u, int p) { for (int i = 0; i < adj[u].size(); i++) { int v = adj[u][i]; if (v == p || bad[v]) continue; if (subtree[v] > tot / 2) return getcenter(v, u); } return u; } void query(int u, int p, int g) { g = _gcd(g, a[u]); for (it = st.begin(); it != st.end(); it++) { int x = *it; int gc = _gcd(g, x); ans[gc] += cnt[x]; } for (int i = 0; i < adj[u].size(); i++) { int v = adj[u][i]; if (v == p || bad[v]) continue; query(v, u, g); } } void update(int u, int p, int g) { g = _gcd(a[u], g); st.insert(g); cnt[g]++; for (int i = 0; i < adj[u].size(); i++) { int v = adj[u][i]; if (v == p || bad[v]) continue; update(v, u, g); } } void decompose(int u, int p) { tot = 0; dfs(u, p); int c = getcenter(u, p); ans[a[c]]++; cnt[a[c]] = 1; st.insert(a[c]); bad[c] = 1; for (int i = 0; i < adj[c].size(); i++) { int v = adj[c][i]; if (v == p || bad[v]) continue; query(v, c, 0); update(v, c, a[c]); } for (it = st.begin(); it != st.end(); it++) { int x = *it; cnt[x] = 0; } st.clear(); for (int i = 0; i < adj[c].size(); i++) { int v = adj[c][i]; if (v == p || bad[v]) continue; decompose(v, c); } } int main() { int t, tc = 1; scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); } for (int i = 1; i < n; i++) { int u, v; scanf("%d %d", &u, &v); adj[u].push_back(v); adj[v].push_back(u); } decompose(1, -1); for (int i = 1; i <= 200000; i++) { if (ans[i]) { printf("%d %lld\n", i, ans[i]); } } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 200020; int n; vector<int> v[N]; vector<int> g[N]; int lab[N]; int sz; int appear[N]; long long save[N]; int changes[N * 40]; long long curr = 0; void recover() { curr = 0; while (sz > 0) lab[changes[sz--]] = -1; } int fin(int u) { if (lab[u] < 0) return u; changes[++sz] = u; return lab[u] = fin(lab[u]); } void join(int u, int v) { u = fin(u); v = fin(v); if (u == v) return; changes[++sz] = u; changes[++sz] = v; if (lab[u] > lab[v]) swap(u, v); curr += 1LL * lab[u] * lab[v]; lab[u] += lab[v]; lab[v] = u; } int main() { scanf("%d", &n); for (int i = 1; i <= n; ++i) { int x; scanf("%d", &x); v[x].push_back(i); } for (int i = 1; i < n; ++i) { int u, v; scanf("%d%d", &u, &v); g[u].push_back(v); g[v].push_back(u); } memset(lab, -1, sizeof lab); for (int i = 200000; i >= 1; --i) { recover(); for (int j = i; j < N; j += i) { save[i] -= (j > i) * (save[j]); for (int x : v[j]) { save[i]++; appear[x] = 1; for (int y : g[x]) { if (appear[y]) join(x, y); } } } save[i] += curr; for (int j = i; j < N; j += i) { for (int x : v[j]) appear[x] = 0; } } for (int i = 1; i < N; ++i) { if (save[i]) printf("%d %lld\n", i, save[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; const long long int N = 2e5 + 5; vector<bool> isprime(N, true), vis(N, false), take(N, false); long long int path = 0; vector<long long int> adj[N], fact[N], mul[N], prime; long long int dfs(long long int u, long long int p = -1) { long long int mx1 = 0, mx2 = 0; vis[u] = true; for (auto v : adj[u]) { if (v != p && take[v]) { long long int sz = dfs(v, u); if (sz > mx1) { mx2 = mx1; mx1 = sz; } else if (sz <= mx1 && sz > mx2) { mx2 = sz; } } } path = max(path, mx1 + mx2 + 1); return mx1 + 1; } signed main() { ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL); long long int t, pro = 1, temp, k, n, m, i, j, l, r, mid, x, y, z, rem, ind, ans = 0, mx = -LONG_LONG_MAX, mn = LONG_LONG_MAX, cnt = 0, curr = 0, prev, sum = 0, flag = 0, i1 = -1, i2 = -1; cin >> n; long long int a[n + 1]; for (i = 2; i <= N - 1; i++) { if (isprime[i]) { prime.push_back(i); for (j = i; j < N; j += i) { isprime[j] = false; fact[j].push_back(i); } } } for (i = 1; i <= n; i++) { cin >> a[i]; for (auto f : fact[a[i]]) { mul[f].push_back(i); } } for (i = 1; i <= n - 1; i++) { cin >> x >> y; adj[x].push_back(y); adj[y].push_back(x); } for (auto p : prime) { for (auto nd : mul[p]) { take[nd] = true; } for (auto nd : mul[p]) { if (!vis[nd]) { dfs(nd); } } for (auto nd : mul[p]) { take[nd] = vis[nd] = false; } } cout << path; return 0; }
#include <bits/stdc++.h> using namespace std; int n, ans; int a[200020], val[200020]; int primo[200020]; vector<int> primos; vector<int> adj[200020]; int vis[200020]; set<int> mult[200020]; void dfs(int u, int last, int p) { if (vis[u] || p == 1 || !mult[u].count(p)) return; vis[u] = val[u] = 1; int mx1 = -1, mx2 = -1; for (int i = (int)0; i < (int)adj[u].size(); i++) { int v = adj[u][i]; if (vis[v]) continue; dfs(v, u, p); if (mx1 == -1) { mx1 = val[v]; } else { if (val[v] >= mx1) { mx2 = mx1; mx1 = val[v]; } else { mx2 = max(mx2, val[v]); } } } if (mx1 != -1) val[u] += mx1; ans = max(ans, val[u]); if (mx2 != -1) ans = max(ans, mx1 + mx2 + 1); } void buildPrimos() { memset(primo, 1, sizeof primo); primo[0] = primo[1] = 0; int fim = sqrt(200002); for (int i = 2; i <= fim; i++) { if (primo[i]) { for (int j = i * i; j <= fim; j += i) primo[j] = 0; } } for (int i = (int)1; i < (int)fim + 1; i++) { if (primo[i]) { primos.push_back(i); } } } int main() { buildPrimos(); scanf("%d", &n); for (int i = (int)1; i < (int)n + 1; i++) scanf("%d", &a[i]); int u, v; for (int i = (int)1; i < (int)n; i++) { scanf("%d %d", &u, &v); adj[u].push_back(v); adj[v].push_back(u); } for (int i = (int)1; i < (int)n + 1; i++) { for (int j = (int)0; j < (int)primos.size(); j++) { if (a[i] % primos[j] == 0) { mult[i].insert(primos[j]); while (a[i] % primos[j] == 0) a[i] /= primos[j]; } } } for (int i = (int)1; i < (int)n + 1; i++) mult[i].insert(a[i]); for (int z = (int)0; z < (int)primos.size(); z++) { memset(vis, 0, sizeof vis); memset(val, 0, sizeof val); for (int i = (int)1; i < (int)n + 1; i++) { dfs(i, i, primos[z]); } } memset(vis, 0, sizeof vis); memset(val, 0, sizeof val); for (int i = (int)1; i < (int)n + 1; i++) { dfs(i, i, a[i]); } cout << ans << '\n'; return 0; }
#include <bits/stdc++.h> using namespace std; template <class t> inline t read(t &x) { x = 0; char c = getchar(); bool f = 0; while (!isdigit(c)) f |= c == '-', c = getchar(); while (isdigit(c)) x = (x << 1) + (x << 3) + (c ^ 48), c = getchar(); if (f) x = -x; return x; } template <class t> inline void write(t x) { if (x < 0) { putchar('-'), write(-x); } else { if (x > 9) write(x / 10); putchar('0' + x % 10); } } const int N = 2e5 + 5; long long cnt[N]; int f[N], sz[N], n, ma, en, h[N], m, id[N], lis[N]; vector<int> val[N]; struct edge { int n, v; } e[N << 1]; inline void add(const int &x, const int &y) { e[++en] = (edge){h[x], y}; h[x] = en; } inline int getf(const int &x) { return f[x] == x ? x : f[x] = getf(f[x]); } inline void swap(int &x, int &y) { x ^= y ^= x ^= y; } inline void unite(int x, int y) { x = getf(x); y = getf(y); if (x == y) return; if (sz[y] < sz[x]) swap(x, y); sz[x] += sz[y]; f[y] = x; } inline int max(const int &x, const int &y) { return x > y ? x : y; } signed main() { read(n); for (int i = 1, x; i <= n; i++) ma = max(ma, read(x)), val[x].push_back(i); for (int i = 1, x, y; i < n; i++) { read(x); read(y); add(x, y); add(y, x); } for (register int i = 1; i <= ma; i++) { m = 0; for (register int j = i; j <= ma; j += i) for (register int k = 0; k < val[j].size(); k++) lis[++m] = val[j][k], sz[m] = 1, f[m] = m, id[val[j][k]] = m; if (!m) continue; cnt[i] = m; for (register int j = 1; j <= m; j++) { int x = lis[j]; for (register int k = h[x]; k; k = e[k].n) { int y = e[k].v; if (!id[y]) continue; unite(id[x], id[y]); } } for (int j = 1; j <= m; j++) { int x = getf(j); if (x == j) cnt[i] += 1ll * sz[x] * (sz[x] - 1) >> 1; } for (register int j = 1; j <= m; j++) id[lis[j]] = 0; } for (register int i = ma; i; i--) for (register int j = i + i; j <= ma; j += i) cnt[i] -= cnt[j]; for (register int i = 1; i <= ma; i++) if (cnt[i]) { write(i); putchar(' '); write(cnt[i]); puts(""); } }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 7; int n, a[N]; vector<int> g[N], fac[N]; int sz[N], rt, minv, sum, cnt1[N], cnt2[N]; bool vis[N]; unsigned long long ans[N]; unsigned long long gcd(unsigned long long a, unsigned long long b) { if (!b) return a; return gcd(b, a % b); } void dfs(int u, int f) { sz[u] = 1; int r = 0; for (int v : g[u]) { if (v == f || vis[v]) continue; dfs(v, u); sz[u] += sz[v]; r = max(r, sz[v]); } r = max(r, sum - sz[u]); if (r < minv) { minv = r; rt = u; } } int dfs2(int u, int f) { int ret = 1; for (int v : g[u]) if (v != f && !vis[v]) ret += dfs2(v, u); return ret; } void dfs3(int u, int f, int gg, int d) { gg = gcd(gg, a[u]); for (int i : fac[gg]) cnt2[i] += d; for (int v : g[u]) if (v != f && !vis[v]) dfs3(v, u, gg, d); } void solve(int u) { for (int i : fac[a[u]]) ans[i]++; bool flag = 0; for (int v : g[u]) { if (vis[v]) continue; dfs3(v, u, 0, 1); if (!flag) { for (int i : fac[a[u]]) ans[i] += cnt2[i]; flag = 1; } else { for (int i : fac[a[u]]) ans[i] += 1LL * (cnt1[i] + 1) * cnt2[i]; } for (int i : fac[a[u]]) cnt1[i] += cnt2[i]; for (int i : fac[a[v]]) cnt2[i] = 0; } for (int i : fac[a[u]]) cnt1[i] = 0; vis[u] = 1; for (int v : g[u]) { if (vis[v]) continue; sum = dfs2(v, u); minv = N; dfs(v, u); solve(rt); } } int main() { ios::sync_with_stdio(0); scanf("%d", &n); for (int i = int(1); i <= int(N - 1); ++i) { for (int j = i; j < N; j += i) fac[j].push_back(i); } for (int i = int(1); i <= int(n); ++i) scanf("%d", a + i); for (int i = int(1); i <= int(n - 1); ++i) { int x, y; scanf("%d%d", &x, &y); g[x].push_back(y); g[y].push_back(x); } minv = N; sum = n; dfs(1, 0); solve(rt); for (int i = int((int)1e5); i >= int(1); --i) { for (int j = i + i; j <= (int)2e5; j += i) ans[i] -= ans[j]; } for (int i = int(1); i <= int((int)2e5); ++i) if (ans[i]) cout << i << " " << ans[i] << endl; }
#include <bits/stdc++.h> using namespace std; const int maxn = 2E5 + 5; const long long int base = 2E5 + 5; int n, val[maxn]; int head[maxn * 2], size; long long int ans[maxn], wait[maxn]; bool vis[maxn]; inline int gcd(int x, int y) { return x % y == 0 ? y : gcd(y, x % y); } struct edge { int to, next; } E[maxn * 2]; inline void add(int u, int v) { E[++size].to = v; E[size].next = head[u]; head[u] = size; } struct note { int x, c; note(int a = 0, int b = 0) { x = a, c = b; } }; queue<note> T[maxn]; vector<note> t; void dfs(int u, int F) { vector<int> what; for (int i = head[u]; i; i = E[i].next) { int v = E[i].to; if (v == F) continue; dfs(v, u); } for (int i = head[u]; i; i = E[i].next) { int v = E[i].to; if (v == F) continue; t.clear(); while (!T[v].empty()) { t.push_back(T[v].front()); T[v].pop(); } for (int j = 0; j < what.size(); ++j) { int x = what[j]; for (int k = 0; k < t.size(); ++k) ans[gcd(x, t[k].x)] += wait[x] * t[k].c; } for (int j = 0; j < t.size(); ++j) { int x = gcd(val[u], t[j].x); if (!vis[x]) { vis[x] = 1; wait[x] = t[j].c; what.push_back(x); } else wait[x] += t[j].c; } } if (!vis[val[u]]) { vis[val[u]] = 1; wait[val[u]] = 1; what.push_back(val[u]); } else ++wait[val[u]]; for (int i = 0; i < what.size(); ++i) { long long int x = what[i]; ans[x] += wait[x]; T[u].push(note(x, wait[x])); vis[x] = wait[x] = 0; } } int main() { ios::sync_with_stdio(false); cin >> n; for (int i = 1; i <= n; ++i) cin >> val[i]; for (int i = 1; i <= n - 1; ++i) { int x, y; cin >> x >> y; add(x, y); add(y, x); } dfs(1, 1); for (int i = 1; i <= 200000; ++i) if (ans[i]) cout << i << " " << ans[i] << endl; return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 1; int a[N]; long long ans[N]; map<int, long long> mp[N]; vector<vector<int> > g; int Gcd(int a, int b) { return (b ? Gcd(b, a % b) : a); } void dfs(int u, int p = -1) { mp[u][a[u]] = 1; ans[a[u]]++; for (auto v : g[u]) { if (v == p) continue; dfs(v, u); for (auto x : mp[u]) for (auto y : mp[v]) ans[Gcd(x.first, y.first)] += 1LL * x.second * y.second; for (auto y : mp[v]) mp[u][Gcd(a[u], y.first)] += y.second; mp[v].clear(); } } void solve() { int n; cin >> n; g.resize(n + 1); for (int i = 1; i <= n; i++) cin >> a[i]; for (int i = 1; i < n; i++) { int u, v; cin >> u >> v; g[u].push_back(v); g[v].push_back(u); } dfs(1); for (int i = 1; i < N; i++) { if (ans[i]) cout << i << ' ' << ans[i] << '\n'; } } signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); solve(); }
#include <bits/stdc++.h> using namespace std; const int N = 200000; int miu[N + 5], prime[N + 5], pcnt; bool not_prime[N + 5]; void shai() { miu[1] = 1; for (int i = 2; i <= N; i++) { if (!not_prime[i]) { pcnt++; prime[pcnt] = i; miu[i] = -1; } for (int j = 1; prime[j] * i <= N; j++) { not_prime[prime[j] * i] = 1; if (i % prime[j] == 0) { miu[prime[j] * i] = 0; break; } miu[prime[j] * i] = -miu[i]; } } } int a[N + 5]; int cnt; vector<int> val[N + 5]; vector<int> G[N + 5]; int good[N + 5]; int vis[N + 5]; long long h[N + 5]; long long ans[N + 5]; int q[N + 5]; int bfs(int x) { int head = 0; int tail = 0; q[tail++] = x; vis[x] = cnt; while (head < tail) { int z = q[head++]; for (int i = 0, sz = G[z].size(); i < sz; i++) { int y = G[z][i]; if (good[a[y]] == cnt && vis[y] < cnt) { vis[y] = cnt; q[tail++] = y; } } } return tail; } int main() { shai(); int n; scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); val[a[i]].push_back(i); } for (int i = 1; i < n; i++) { int x, y; scanf("%d%d", &x, &y); G[x].push_back(y); G[y].push_back(x); } for (int i = N; i > 0; i--) { cnt++; for (int j = i; j <= N; j += i) good[j] = cnt; for (int j = i; j <= N; j += i) for (int k = 0, sz = val[j].size(); k < sz; k++) { int x = val[j][k]; if (vis[x] == cnt) continue; int z = bfs(x); h[i] += 1ll * z * (z + 1) / 2; } for (int j = i, k = 1; j <= N; j += i, k++) ans[i] += miu[k] * h[j]; } for (int i = 1; i <= N; i++) if (ans[i] > 0) printf("%d %I64d\n", i, ans[i]); }
#include <bits/stdc++.h> using namespace std; const int maxn = 200005; int a[maxn]; int dp[maxn][10]; vector<int> G[maxn]; vector<int> vec[maxn]; map<pair<int, int>, int> mp; int ans; void dfs(int x, int fa) { for (int i = 0; i < G[x].size(); i++) dp[x][i] = 1; int f1[10], f2[10]; memset(f1, 0, sizeof(f1)); memset(f2, 0, sizeof(f2)); for (int i = 0; i < vec[x].size(); i++) { int to = vec[x][i]; if (to == fa) continue; dfs(to, x); for (int j = 0; j < G[x].size(); j++) { if (a[to] % G[x][j] == 0) { int pos = mp[pair<int, int>(G[x][j], to)]; int tmp = dp[to][pos]; if (f1[j] < tmp) { f2[j] = f1[j]; f1[j] = tmp; } else if (f2[j] < tmp) { f2[j] = tmp; } } } } for (int i = 0; i < G[x].size(); i++) { dp[x][i] += f1[i]; ans = max(ans, f1[i] + f2[i] + 1); } return; } int main() { ios::sync_with_stdio(false); int n, u, v; cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; int tmp = a[i]; for (int j = 2; j * j <= tmp; j++) { if (tmp % j == 0) { G[i].push_back(j); mp[pair<int, int>(j, i)] = G[i].size() - 1; while (tmp % j == 0) tmp /= j; } } if (tmp > 1) { G[i].push_back(tmp); mp[pair<int, int>(tmp, i)] = G[i].size() - 1; } } for (int i = 1; i <= n - 1; i++) { cin >> u >> v; vec[u].push_back(v); vec[v].push_back(u); } dfs(1, -1); cout << ans << endl; return 0; }
#include <bits/stdc++.h> using namespace std; namespace SHENZHEBEI { static const int GYN = 2333333; char SZB[GYN], *SS = SZB, *TT = SZB; inline char gc() { if (SS == TT) { TT = (SS = SZB) + fread(SZB, 1, GYN, stdin); if (SS == TT) return '\n'; } return *SS++; } inline long long read() { long long x = 0, g = 1; char ch = gc(); for (; !isdigit(ch); ch = gc()) if (ch == '-') g = -1; for (; isdigit(ch); ch = gc()) x = x * 10 - 48 + ch; return x * g; } inline void write(long long x) { if (x < 0) putchar('-'), x = -x; if (x >= 10) write(x / 10); putchar(x % 10 + '0'); } inline char readchar() { char ch = gc(); for (; isspace(ch); ch = gc()) ; return ch; } inline long long readstr(char *s) { char ch = gc(); int cur = 0; for (; isspace(ch); ch = gc()) ; for (; !isspace(ch); ch = gc()) s[cur++] = ch; s[cur] = '\0'; return cur; } void Print(long long *a, int s, int t) { for (int i = int(s); i <= int(t); ++i) printf("%lld ", a[i]); } void Print(int *a, int s, int t) { for (int i = int(s); i <= int(t); ++i) printf("%d ", a[i]); } void Print(char *a, int s, int t) { for (int i = int(s); i <= int(t); ++i) putchar(a[i]); } void writeln(long long x) { write(x); puts(""); } } // namespace SHENZHEBEI using namespace SHENZHEBEI; const long long N = 200010; vector<int> g[N], h[N]; long long id[N], a[N], sum[N], answ[N], fa[N], dep[N], vis[N], ok[N], n, cnt, cogito; void dfs(long long x) { for (int i = int(0); i < int(g[x].size()); ++i) { long long to = g[x][i]; if (to == fa[x]) continue; dep[to] = dep[x] + 1; fa[to] = x; dfs(to); } } void insert(long long x, long long w) { cnt = 0; for (long long i = 1; i * i <= w; i++) if (!(w % i)) { h[i].push_back(x); ++cnt; if (i * i != w) h[w / i].push_back(x); ++cnt; } ((cogito) = ((cogito) < (cnt) ? (cnt) : (cogito))); } bool cmp(long long a, long long b) { return dep[a] > dep[b]; } int main() { n = read(); for (int i = int(1); i <= int(n); ++i) id[i] = i; for (int i = int(1); i <= int(n); ++i) a[i] = read(); for (int i = int(1); i < int(n); ++i) { long long x = read(), y = read(); g[x].push_back(y); g[y].push_back(x); } dfs(1); sort(id + 1, id + n + 1, cmp); for (int i = int(1); i <= int(n); ++i) insert(id[i], a[id[i]]); for (int val = int(1); val <= int(200000); ++val) { for (int i = int(0); i < int(h[val].size()); ++i) ok[i] = h[val][i]; long long Sum = h[val].size(); long long ans = 0; for (int i = int(0); i < int(Sum); ++i) vis[ok[i]] = val, sum[ok[i]] = 1; for (int i = int(0); i < int(Sum); ++i) { long long x = ok[i]; if (vis[fa[x]] != val) ans += sum[x] * (sum[x] + 1) >> 1; else sum[fa[x]] += sum[x]; } answ[val] = ans; } for (int i = int(200000); i >= int(1); --i) for (long long j = 2 * i; j <= 200000; j += i) answ[i] -= answ[j]; for (int i = int(1); i <= int(200000); ++i) if (answ[i]) write(i), putchar(' '), writeln(answ[i]); }
#include <bits/stdc++.h> using namespace std; static inline void canhazfast() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); } template <typename T> T gcd(T a, T b) { return b == 0 ? a : gcd(b, a % b); } template <typename T> T extgcd(T a, T b, T &x, T &y) { T x0 = 1, y0 = 0, x1 = 0, y1 = 1; while (b) { T q = a / b; a %= b; swap(a, b); x0 -= q * x1; swap(x0, x1); y0 -= q * y1; swap(y0, y1); } x = x0; y = y0; return a; } static inline int ctz(unsigned x) { return __builtin_ctz(x); } static inline int ctzll(unsigned long long x) { return __builtin_ctzll(x); } static inline int clz(unsigned x) { return __builtin_clz(x); } static inline int clzll(unsigned long long x) { return __builtin_clzll(x); } static inline int popcnt(unsigned x) { return __builtin_popcount(x); } static inline int popcntll(unsigned long long x) { return __builtin_popcountll(x); } static inline int bsr(unsigned x) { return 31 ^ clz(x); } static inline int bsrll(unsigned long long x) { return 63 ^ clzll(x); } int a[200008]; int id[200008]; int sz[200008]; int rk[200008]; void rst(int x) { id[x] = x; sz[x] = 1; rk[x] = 0; } int fin(int x) { return id[x] == x ? x : id[x] = fin(id[x]); } void uni(int x, int y) { if (rk[x] < rk[y]) { id[x] = y; sz[y] += sz[x]; } else { id[y] = x; sz[x] += sz[y]; rk[x] = max(rk[x], rk[y] + 1); } } vector<int> vs[200008]; vector<pair<int, int> > es[200008]; long long ans[200008]; int main() { canhazfast(); int n, amx = 0; cin >> n; for (int i = 1; i <= n; ++i) { cin >> a[i]; amx = max(amx, a[i]); vs[a[i]].push_back(i); } for (int i = 1; i < n; ++i) { int x, y; cin >> x >> y; es[gcd(a[x], a[y])].push_back(make_pair(x, y)); } for (int i = amx; i > 0; --i) { long long res = 0; for (int j = i; j <= amx; j += i) { res += (long long)vs[j].size(); for (int v : vs[j]) rst(v); if (j > i) res -= ans[j]; } for (int j = i; j <= amx; j += i) { for (pair<int, int> e : es[j]) { int x = fin(e.first), y = fin(e.second); res += (long long)sz[x] * sz[y]; uni(x, y); } } ans[i] = res; } for (int i = 1; i <= amx; ++i) if (ans[i]) cout << i << ' ' << ans[i] << '\n'; return 0; }
#include <bits/stdc++.h> using namespace std; const double PI = 2 * acos(0.0); template <class T> void show(const vector<T> &a) { for (T x : a) cout << x << " "; cout << endl; } const int N = 2e5 + 1; vector<int> g[N]; int a[N]; long long ans[N]; int gcd(int a, int b) { if (a < b) swap(a, b); while (b) { a %= b; swap(a, b); } return a; } vector<int> get(int); vector<pair<int, int> > trans(const vector<pair<int, int> > &a, int nfrom, int nto) { vector<int> to = get(nto); vector<int> ret(((int)(to.size())), 0); for (auto x : a) { int g = gcd(nto, x.first); g = lower_bound(to.begin(), to.end(), g) - to.begin(); ret[g] += x.second; } vector<pair<int, int> > real_ret; for (int i = 0; i < int(((int)(to.size()))); ++i) { if (ret[i]) real_ret.push_back(make_pair(to[i], ret[i])); } return real_ret; } vector<int> get(int n) { vector<int> ret; for (int i = 1; i * i <= n; ++i) if (!(n % i)) { ret.push_back(i); if (i != n / i) ret.push_back(n / i); } sort(ret.begin(), ret.end()); return ret; } void my_merge(vector<pair<int, int> > &a, const vector<pair<int, int> > &b) { vector<pair<int, int> > ret; int na = 0; int nb = 0; while (na < ((int)(a.size())) && nb < ((int)(b.size()))) { if (a[na].first == b[nb].first) { ret.push_back(make_pair(a[na].first, a[na].second + b[nb].second)); ++na; ++nb; } else if (a[na].first < b[nb].first) { ret.push_back(a[na]); ++na; } else { ret.push_back(b[nb]); ++nb; } } while (na < ((int)(a.size()))) ret.push_back(a[na++]); while (nb < ((int)(b.size()))) ret.push_back(b[nb++]); a = ret; } vector<pair<int, int> > dfs(int v, int par, vector<pair<int, int> > up) { vector<pair<int, int> > sum = up; vector<pair<int, int> > ret; ret.push_back(make_pair(a[v], 1)); for (int to : g[v]) { if (to == par) continue; vector<pair<int, int> > kek = dfs(to, v, trans(sum, a[v], a[to])); kek = trans(kek, a[to], a[v]); my_merge(ret, kek); my_merge(sum, kek); } for (auto x : ret) ans[x.first] += x.second; for (auto x : up) ans[x.first] += x.second; return ret; } int cnt[N]; void cnt_dfs(int v, int par) { cnt[v] = 1; for (int to : g[v]) if (to != par) { cnt_dfs(to, v); cnt[v] += cnt[to]; } } void find_str(int v, int par, int &c, int n) { bool ok = 1; if (n - cnt[v] > n / 2) ok = 0; for (int to : g[v]) { if (to == par) continue; if (cnt[to] > n / 2) ok = 0; } if (ok) c = v; for (int to : g[v]) if (to != par) find_str(to, v, c, n); } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int n; cin >> n; for (int i = 0; i < int(n); ++i) cin >> a[i + 1]; for (int iter = 0; iter < int(n - 1); ++iter) { int u, v; cin >> u >> v; g[u].push_back(v); g[v].push_back(u); } cnt_dfs(1, -1); int c = 1; find_str(1, -1, c, n); dfs(c, -1, {}); for (int i = 0; i < int(N); ++i) if (ans[i]) cout << i << " " << ans[i] << "\n"; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 7; int n; int a[N], f[N], sz[N]; long long Ans[N]; vector<int> ve[N], g[N]; inline int find(int x) { return f[x] == x ? x : f[x] = find(f[x]); } int main() { scanf("%d", &n); for (int i = 1; i <= n; ++i) scanf("%d", &a[i]), g[a[i]].push_back(i); for (int i = 1, x, y; i < n; ++i) scanf("%d%d", &x, &y), ve[x].push_back(y), ve[y].push_back(x); for (int i = 1; i < N; ++i) { long long ans = 0; for (int j = i; j < N; j += i) for (auto x : g[j]) f[x] = x, sz[x] = 1, ++ans; for (int j = i; j < N; j += i) for (auto x : g[j]) for (auto y : ve[x]) if (a[y] % i == 0 && find(x) != find(y)) { ans += 1ll * sz[f[x]] * sz[f[y]]; sz[f[x]] += sz[f[y]]; f[f[y]] = f[x]; } Ans[i] = ans; } for (int i = N - 1; i; --i) for (int j = i + i; j < N; j += i) Ans[i] -= Ans[j]; for (int i = 1; i < N; ++i) if (Ans[i]) printf("%d %lld\n", i, Ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> inline void read(T &x) { x = 0; bool flag = 0; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) if (ch == 45) flag = 1; for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - 48; if (flag) x = -x; } int n, a[200010], mx[200010], siz[200010], sum, root; long long ans[200010]; vector<int> g[200010]; bool vis[200010]; int gcd(int a, int b) { return b ? gcd(b, a % b) : a; } void getRoot(int u, int fa) { siz[u] = 1, mx[u] = 0; for (auto v : g[u]) if (v != fa && !vis[v]) getRoot(v, u), siz[u] += siz[v], mx[u] = max(mx[u], siz[v]); mx[u] = max(mx[u], sum - siz[u]); if (mx[u] < mx[root]) root = u; } map<int, int> mp, tp; void getAns(int u, int fa, int num) { tp[num]++; for (auto v : g[u]) if (v != fa && !vis[v]) getAns(v, u, gcd(num, a[v])); } void dfs(int u) { vis[u] = 1; mp.clear(), mp[a[u]]++, ans[a[u]]++; for (auto v : g[u]) if (!vis[v]) { tp.clear(), getAns(v, u, gcd(a[u], a[v])); for (auto it1 : mp) for (auto it2 : tp) ans[gcd(it1.first, it2.first)] += (long long)it1.second * it2.second; for (auto it : tp) mp[it.first] += it.second; } for (auto v : g[u]) if (!vis[v]) root = 0, sum = siz[v], getRoot(v, 0), dfs(root); } int main() { read(n); int gay = 0; for (int i = 1; i <= n; i++) read(a[i]), gay = max(gay, a[i]); for (int i = 2; i <= n; i++) { int u, v; read(u), read(v); g[u].push_back(v), g[v].push_back(u); } sum = mx[0] = n; getRoot(1, 0); dfs(root); for (int i = 1; i <= gay; i++) if (ans[i]) printf("%d %lld\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 5; int n; vector<int> graph[MAXN]; int a[MAXN]; void read_input() { scanf("%d", &n); for (int i = 0; i < n; i++) { scanf("%d", &a[i + 1]); } int v, w; for (int i = 0; i < n - 1; i++) { scanf("%d %d", &v, &w); graph[v].push_back(w); graph[w].push_back(v); } } int br; int cnt[MAXN]; bool used[MAXN]; void dfs(int v, int p) { br++; cnt[v] = 1; for (auto x : graph[v]) { if (x != p && !used[x]) { dfs(x, v); cnt[v] += cnt[x]; } } } int get_centroid(int v, int p) { for (auto x : graph[v]) { if (x != p && !used[x] && cnt[x] >= (br >> 1)) { return get_centroid(x, v); } } return v; } map<int, long long> mp, mp2, ans; int _gcd(int a, int b) { if (b == 0) return a; return _gcd(b, a % b); } void mark(int v, int p, int gc) { mp2[gc]++; for (auto x : graph[v]) { if (x == p || used[x]) { continue; } mark(x, v, _gcd(gc, a[x])); } } void rec(int v) { br = 0; dfs(v, v); int cen = get_centroid(v, v); used[cen] = true; mp.clear(); ans[a[cen]]++; for (auto x : graph[cen]) { if (!used[x]) { mp2.clear(); mark(x, cen, _gcd(a[cen], a[x])); for (auto z : mp2) { ans[z.first] += z.second; for (auto g : mp) { ans[_gcd(z.first, g.first)] += 1LL * z.second * g.second; } } for (auto z : mp2) { mp[z.first] += z.second; } } } for (auto x : graph[cen]) { if (!used[x]) { rec(x); } } } void solve() { rec(1); for (auto z : ans) { printf("%d %lld\n", z.first, z.second); } } int main() { read_input(); solve(); return 0; }
#include <bits/stdc++.h> using namespace std; vector<vector<long long>> factors(200001, vector<long long>(1, 1)); void precompute() { for (long long i = 2; i < 200001; ++i) { for (long long j = i; j < 200001; j += i) { factors[j].push_back(i); } } } struct Centroid { long long total = 0; vector<long long> dead, sz, freq, ans, pre, weight, temp; long long subtree(long long a, long long p, vector<vector<long long>>& tree) { sz[a] = 1; for (long long& c : tree[a]) if (c != p && !dead[c]) sz[a] += subtree(c, a, tree); return sz[a]; } long long OneCentroid(long long a, long long p, long long s, vector<vector<long long>>& tree) { for (long long& c : tree[a]) if (c != p && !dead[c] && sz[c] > (s >> 1)) return OneCentroid(c, a, s, tree); return a; } void change(long long a, long long p, long long ch, vector<vector<long long>>& tree) { for (long long& i : factors[pre[a]]) freq[i] += ch; for (long long& c : tree[a]) if (c != p && !dead[c]) change(c, a, ch, tree); } void computeans(long long a, long long p, vector<vector<long long>>& tree) { for (long long& i : factors[pre[a]]) temp[i] = freq[i]; for (auto it = factors[pre[a]].rbegin(); it != factors[pre[a]].rend(); it++) { if (temp[*it] == 0) continue; for (long long& c : factors[*it]) if (*it != c) temp[c] -= temp[*it]; } for (long long& f : factors[pre[a]]) ans[f] += temp[f], temp[f] = 0; for (long long& c : tree[a]) if (c != p && !dead[c]) computeans(c, a, tree); } long long gcd(long long a, long long b) { return (a == 0) ? b : gcd(b % a, a); } void compute(long long a, long long p, long long d, vector<vector<long long>>& tree) { for (long long& i : factors[pre[a] = d]) freq[i]++; for (long long& c : tree[a]) if (c != p && !dead[c]) compute(c, a, gcd(d, weight[c]), tree); } void decompose(long long a, long long p, vector<vector<long long>>& tree) { long long cent = OneCentroid(a, p, subtree(a, p, tree), tree); compute(cent, -1, weight[cent], tree); dead[cent] = 1; for (long long& c : tree[cent]) if (!dead[c]) { change(c, cent, -1, tree); computeans(c, cent, tree); } for (long long& f : factors[pre[cent]]) freq[f]--; ans[weight[cent]]++; for (long long& c : tree[cent]) if (!dead[c]) decompose(c, cent, tree); } Centroid(vector<vector<long long>>& tree, long long N, vector<long long>& w) : weight(w) { dead.assign(N, 0); sz.assign(N, 0); pre.assign(N, 0); temp.assign(200001, 0); ans.assign(200001, 0); freq.assign(200001, 0); decompose(0, -1, tree); for (long long i = 0; i < 200001; ++i) { if (ans[i]) cout << i << ' ' << ans[i] << '\n'; } } }; signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); long long N; cin >> N; vector<vector<long long>> tree(N); vector<long long> w(N); for (long long& i : w) cin >> i; for (long long i = 1, u, v; i < N; ++i) { cin >> u >> v; --u, --v; tree[u].push_back(v); tree[v].push_back(u); } precompute(); Centroid ans(tree, N, w); return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 200010; int n, par[maxn], rot[maxn], sz[maxn]; vector<int> divs[maxn], g[maxn], subt[maxn], vers[maxn]; long long cnt[maxn]; void dfs(int x, int parx) { for (auto y : g[x]) if (y != parx) par[y] = x, dfs(y, x); } int root(int x) { return rot[x] == x ? x : rot[x] = root(rot[x]); } int main() { ios::sync_with_stdio(false), cin.tie(0), cout.tie(0); for (int i = 2; i < maxn; ++i) { for (int j = i; j < maxn; j += i) divs[j].emplace_back(i); } cin >> n; for (int i = 0; i < n; ++i) { int x; cin >> x; for (auto d : divs[x]) vers[d].emplace_back(i + 1); } for (int i = 0; i < n - 1; ++i) { int a, b; cin >> a >> b; g[a].emplace_back(b), g[b].emplace_back(a); } g[0].emplace_back(1); dfs(0, 0); cnt[1] = 1LL * n * (n + 1) / 2; iota(rot, rot + n + 1, 0); for (int d = 2; d < maxn; ++d) { for (auto v : vers[d]) { sz[v] = 1; ++cnt[d]; if (sz[par[v]]) { rot[v] = root(par[v]); cnt[d] += sz[rot[v]]; sz[rot[v]] += sz[v]; } else subt[par[v]].emplace_back(v); root(v); for (auto ch : subt[v]) { rot[ch] = rot[v]; cnt[d] += 1LL * sz[rot[v]] * sz[ch]; sz[rot[v]] += sz[ch]; } } for (auto v : vers[d]) { sz[v] = 0; subt[par[v]].clear(); rot[v] = v; } } for (int i = (maxn)-1; i >= 1; --i) { for (int j = i + i; j < maxn; j += i) cnt[i] -= cnt[j]; } for (int i = 1; i < maxn; ++i) if (cnt[i]) { cout << i << ' ' << cnt[i] << '\n'; } }
#include <bits/stdc++.h> using namespace std; const int MAXN = (int)2e5 + 5; vector<int> g[MAXN]; vector<pair<int, int> > values[MAXN]; const int INF = 1000000000; int spf[200001]; void initSPF() { for (int i = 0; i < 200001; i++) spf[i] = INF; for (int i = 2; i < 200001; i++) { if (spf[i] != INF) continue; for (int j = 1; j * i < 200001; j++) { spf[i * j] = min(spf[i * j], i); } } } int mxx = 0; int vals[MAXN]; void dfs(int node, int pp) { vector<int> primes; int k = vals[node]; while (k > 1) { if (primes.size() > 0 and primes[primes.size() - 1] == spf[k]) { k /= spf[k]; continue; } primes.push_back(spf[k]); k /= spf[k]; } for (int i = 0; i < g[node].size(); i++) { int child = g[node][i]; if (child == pp) continue; dfs(child, node); } int mx = 0; for (int i = 0; i < primes.size(); i++) { int p = primes[i]; int val = 0; int val2 = 0; for (int j = 0; j < g[node].size(); j++) { int child = g[node][j]; if (child == pp) continue; int ans = lower_bound(values[child].begin(), values[child].end(), make_pair(p, 0)) - values[child].begin(); if (ans < values[child].size() and values[child][ans].first == p) { int vs = values[child][ans].second; if (val == -1) { val = vs; } else { if (vs > val) { val2 = val; val = vs; } else if (vs > val2) val2 = vs; } } } mx = val + val2 + 1; mxx = max(mxx, mx); values[node].push_back(make_pair(p, val + 1)); } sort(values[node].begin(), values[node].end()); for (int j = 0; j < values[node].size(); j++) { } } int main() { int n; cin >> n; for (int i = 0; i < n; i++) cin >> vals[i]; initSPF(); for (int i = 0; i < n - 1; i++) { int a, b; cin >> a >> b; a--; b--; g[a].push_back(b); g[b].push_back(a); } bool ok = 0; for (int i = 0; i < n; i++) if (vals[i] > 1) ok = 1; if (!ok) { cout << 0 << endl; return 0; } dfs(0, -1); for (int i = 0; i < n; i++) { for (int j = 0; j < values[i].size(); j++) { } } cout << mxx << endl; return 0; }
#include <bits/stdc++.h> using namespace std; #pragma GCC optimize("O3") #pragma GCC target("sse4") const double PI = acos(-1.0); const double EPS = 1e-9; const long long INF = 1e9; const long long LINF = 1e18; const long long mod = 1e9 + 7; const long long MAX = 2e5 + 7; int n; int a[MAX]; vector<int> g[MAX]; long long DP[MAX]; vector<int> vert[MAX]; bool ye[MAX]; bool pozn[MAX]; int marked[MAX]; int counter = 0; int q[MAX]; int main() { scanf("%d", &n); for (int i = (0); i < (n); ++i) { scanf("%d", &a[i]); vert[a[i]].push_back(i); } int u, v; for (int i = (0); i < (n - 1); ++i) { scanf("%d %d", &u, &v); --u; --v; g[u].push_back(v); g[v].push_back(u); } for (int i = (1); i < (MAX); ++i) { counter = 0; for (int j = i; j < MAX; j += i) { int k; for (int to = (0); to < ((int)((vert[j]).size())); ++to) { k = vert[j][to]; marked[counter++] = k; ye[k] = 1; pozn[k] = 0; } } long long tut = 0; for (int to = (0); to < (counter); ++to) { int k = marked[to]; if (pozn[k]) continue; int poch = 0, kinec = 0; q[0] = k; pozn[k] = 1; int ye1 = 1; while (poch <= kinec) { int t = q[poch++]; for (int to = (0); to < ((int)((g[t]).size())); ++to) { int su = g[t][to]; if (pozn[su] || ye[su] == 0) continue; pozn[su] = 1; ++ye1; q[++kinec] = su; } } tut += ye1 * 1LL * (ye1 - 1) / 2LL; } DP[i] = tut; for (int k = (0); k < (counter); ++k) ye[marked[k]] = 0; } for (int i = (MAX)-1; i >= (1); --i) for (int j = i * 2; j < MAX; j += i) DP[i] -= DP[j]; for (int i = (1); i < (MAX); ++i) DP[i] += (int)((vert[i]).size()); for (int i = (1); i < (MAX); ++i) if (DP[i]) { printf("%d ", i); printf("%lld\n", DP[i]); } return 0; }
#include <bits/stdc++.h> #pragma GCC optimize(3) using namespace std; long long n, k, a[200005]; long long p[200005], r[200005], sz[200005], ans[200005]; vector<pair<int, int> > G[200005]; vector<int> v[200005]; long long cur; long long gcd(long long a, long long b) { if (b == 0) return a; return gcd(b, a % b); } long long find(long long x) { if (p[x] == x) return x; else return p[x] = find(p[x]); } void unite(long long x, long long y) { x = find(x); y = find(y); if (x == y) return; cur -= sz[x] * (sz[x] - 1) / 2; cur -= sz[y] * (sz[y] - 1) / 2; p[x] = y; sz[y] += sz[x]; cur += sz[y] * (sz[y] - 1) / 2; } int main() { scanf("%lld", &n); for (long long i = 1; i <= n; i++) { scanf("%lld", &a[i]); v[a[i]].push_back(i); } for (long long i = 0; i < n - 1; i++) { long long u, v; scanf("%lld%lld", &u, &v); G[gcd(a[u], a[v])].push_back(pair<int, int>(u, v)); } for (long long i = 1; i <= 200000; i++) { cur = 0; for (long long j = i; j <= 200000; j += i) { for (long long k = 0; k < (int)v[j].size(); k++) { long long node = v[j][k]; p[node] = node, sz[node] = 1; cur++; } } for (long long j = i; j <= 200000; j += i) { for (long long k = 0; k < (int)G[j].size(); k++) { pair<int, int> e = G[j][k]; unite(e.first, e.second); } } ans[i] = cur; } for (long long i = 200000; i >= 1; i--) for (long long j = 2 * i; j <= 200000; j += i) ans[i] -= ans[j]; for (long long i = 1; i <= 200000; i++) if (ans[i]) printf("%lld %lld\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; vector<vector<int> > adj(200001), vertices(200001); bool marked[200001]; long long ans[200001]; int DFS(int i) { marked[i] = 0; int ans = 1; for (auto k : adj[i]) { if (marked[k]) { ans += DFS(k); } } return ans; } int main() { int n; scanf("%d", &n); for (int i = 1; i <= n; ++i) { int x; scanf("%d", &x); vertices[x].push_back(i); } for (int x = 1; x < n; ++x) { int i, j; scanf("%d%d", &i, &j); adj[i].push_back(j); adj[j].push_back(i); } for (int i = 200001 - 1; i > 0; --i) { vector<int> v; for (int j = i; j < 200001; j += i) { for (auto x : vertices[j]) { v.push_back(x); marked[x] = 1; } } long long val = 0; for (auto x : v) { if (marked[x] == 0) continue; long long valx = DFS(x); val += (valx * (valx + 1) / 2); } ans[i] = val; for (int j = i + i; j < 200001; j += i) ans[i] -= ans[j]; } for (int i = 1; i < 200001; ++i) { if (ans[i]) { printf("%d %lld\n", i, ans[i]); } } return 0; }
#include <bits/stdc++.h> using namespace std; int lg(long long n) { assert(n > 0); int ans = -1; while (n) { ans++; n >>= 1; } return ans; } void solve() { const int M = 2e5; vector<int> mobius(M + 1), par(M + 1), pri; for (int i = 1; i <= M; i++) { if (i == 1) mobius[i] = 1; else { if (!par[i]) { pri.push_back(i); par[i] = i; mobius[i] = -1; } for (int x : pri) { if (x > M / i) break; mobius[x * i] = -mobius[i]; par[x * i] = x; if (x == par[i]) { mobius[x * i] = 0; break; } } } } int n; cin >> n; vector<int> a(n); for (int i = 0; i < n; i++) cin >> a[i]; vector<vector<int>> adj(n); for (int i = 1; i < n; i++) { int u, v; cin >> u >> v; u--, v--; adj[u].push_back(v); adj[v].push_back(u); } vector<vector<int>> idxbyval(M + 1); for (int i = 0; i < n; i++) idxbyval[a[i]].push_back(i); vector<int> vis(n), ingraph(n); int cnt = 0; function<void(int, int)> dfs = [&](int cur, int fa) { vis[cur] = 1; cnt++; for (int nxt : adj[cur]) { if (ingraph[nxt] && !vis[nxt]) { dfs(nxt, cur); } } }; vector<long long> ans(M + 1); for (int i = 1; i <= M; i++) { vector<int> subgraph; for (int x = i; x <= M; x += i) { for (int idx : idxbyval[x]) { subgraph.push_back(idx); ingraph[idx] = 1; } } if (subgraph.empty()) continue; for (int idx : subgraph) { if (!vis[idx]) { cnt = 0; dfs(idx, -1); ans[i] += 1LL * cnt * (cnt + 1) / 2; } } for (int idx : subgraph) { ingraph[idx] = vis[idx] = 0; } } vector<long long> ans2(M + 1); for (int mul = 1; mul <= M; mul++) { if (mobius[mul] == 0) continue; for (int i = 1; i * mul <= M; i++) { ans2[i] += (mobius[mul] == 1 ? ans[i * mul] : -ans[i * mul]); } } for (int i = 1; i <= M; i++) { if (ans2[i] != 0) { cout << i << ' ' << ans2[i] << '\n'; } } } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); int t = 1; while (t--) solve(); return 0; }
#include <bits/stdc++.h> using namespace std; const int INF = 0x3f3f3f3f; const long long INFF = 0x3f3f3f3f3f3f3f3fll; const long long M = 1e9 + 7; const long long maxn = 1e6 + 7; const double pi = acos(-1.0); const double eps = 0.00000001; long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; } template <typename T> inline T abs(T a) { return a > 0 ? a : -a; } template <typename T> inline T powMM(T a, T b) { T ret = 1; for (; b; b >>= 1ll, a = (long long)a * a % M) if (b & 1) ret = (long long)ret * a % M; return ret; } int A[maxn]; vector<int> edge[maxn]; int sz[maxn]; bool mark[maxn]; int minweight, root; void dfs1(int x, int fa, int n) { int weight = 0; sz[x] = 1; for (int v : edge[x]) { if (v == fa || mark[v]) continue; dfs1(v, x, n); sz[x] += sz[v]; weight = max(weight, sz[v]); } weight = max(weight, n - sz[x]); if (weight < minweight) root = x, minweight = weight; } map<int, int> now; map<int, int> MP; map<int, long long> ans; void dfs2(int x, int fa, int gg) { gg = gcd(gg, A[x]); now[gg]++; for (int v : edge[x]) { if (v == fa || mark[v]) continue; dfs2(v, x, gg); } } unordered_map<long long, int> MMP; inline int getgcd(int x, int y) { if (MMP[(long long)x * 1000000 + y]) return MMP[(long long)x * 1000000 + y]; else return MMP[(long long)x * 1000000 + y] = gcd(x, y); } void calc(int x) { MP.clear(); MP[A[x]]++; for (int u : edge[x]) { if (mark[u]) continue; now.clear(); dfs2(u, x, A[x]); for (auto P : now) for (auto Q : MP) ans[getgcd(P.first, Q.first)] += (long long)Q.second * P.second; for (auto P : now) MP[P.first] += P.second; } MP.clear(); } void dfs3(int x) { calc(x); mark[x] = 1; ans[A[x]]++; for (int v : edge[x]) { if (mark[v]) continue; minweight = sz[v]; dfs1(v, 0, sz[v]); dfs3(root); } } int main() { int i, j, n; scanf("%d", &n); for (i = 1; i <= n; i++) scanf("%d", &A[i]); for (i = 1; i <= n - 1; i++) { int u, v; scanf("%d%d", &u, &v); edge[u].push_back(v); edge[v].push_back(u); } minweight = n; dfs1(1, 0, n); dfs3(root); for (auto now : ans) printf("%d %I64d\n", now.first, now.second); }
#include <bits/stdc++.h> #pragma GCC optimize("O3") using namespace std; const int N = 1200031; int n, ar[N], w[N]; int gcd(int a, int b) { while (a && b) a > b ? a %= b : b %= a; return a + b; } vector<pair<int, int> > edges; vector<int> entries[N]; int sz[N]; long long ANS[N]; vector<int> interesting; long long cur_pairs; void run_cleanup() { for (int i = 0; i < interesting.size(); i++) { int id = interesting[i]; sz[id] = 1; w[id] = id; } } int get(int x) { interesting.push_back(x); if (x == w[x]) return x; return w[x] = get(w[x]); } long long F(int x) { return 1ll * x * (x - 1) / 2; } void merge(int a, int b) { a = get(a); b = get(b); if (a == b) return; cur_pairs -= F(sz[a]); cur_pairs -= F(sz[b]); w[a] = b; sz[b] += sz[a]; cur_pairs += F(sz[b]); } vector<int> divs[N]; int main() { ios_base::sync_with_stdio(0); cin >> n; for (int i = 1; i <= n; i++) { cin >> ar[i]; } for (int i = 1; i < n; i++) { int a, b; cin >> a >> b; edges.push_back(make_pair(a, b)); } for (int i = 0; i < edges.size(); i++) { int here = gcd(ar[edges[i].first], ar[edges[i].second]); entries[here].push_back(i); } for (int i = 1; i <= n; i++) { w[i] = i; sz[i] = 1; } for (int i = 1; i <= 200000; i++) { interesting.clear(); cur_pairs = 0; for (int j = i; j <= 200000; j += i) { for (int q = 0; q < entries[j].size(); q++) { int id = entries[j][q]; merge(edges[id].first, edges[id].second); } } ANS[i] = cur_pairs; run_cleanup(); } for (int i = 1; i <= 200000; i++) { for (int j = i * 2; j <= 200000; j += i) divs[j].push_back(i); } for (int i = 200000; i; --i) { for (int j = 0; j < divs[i].size(); j++) { int p = divs[i][j]; ANS[p] -= ANS[i]; } } for (int i = 1; i <= n; i++) { ANS[ar[i]]++; } for (int i = 1; i <= 200000; i++) { if (ANS[i]) cout << i << " " << ANS[i] << endl; } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 7; vector<int> ind[N]; vector<int> adj[N]; int a[N], cnt[N]; bool av[N]; long long ans[N]; vector<int> factors[N]; void pre() { for (int i = 1; i < N; i++) for (int j = i; j < N; j += i) factors[j].push_back(i); } int dfs(int u) { int ans = 1; av[u] = 0; for (auto v : adj[u]) if (av[v]) ans += dfs(v); return ans; } int main() { ios::sync_with_stdio(0); cin.tie(0); pre(); int n; cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; for (auto d : factors[a[i]]) ind[d].push_back(i); cnt[a[i]]++; } for (int i = 1; i < n; i++) { int x, y; cin >> x >> y; adj[x].push_back(y); adj[y].push_back(x); } for (int i = 1; i < N; i++) { for (auto v : ind[i]) av[v] = true; for (auto v : ind[i]) if (av[v]) { int cnt = dfs(v); ans[i] += 1LL * cnt * cnt; } } for (int i = N - 1; i > 0; i--) for (int j = 2 * i; j < N; j += i) ans[i] -= ans[j]; for (int i = 1; i < N; i++) { ans[i] += cnt[i]; ans[i] /= 2; } for (int i = 1; i < N; i++) if (ans[i]) cout << i << " " << ans[i] << "\n"; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 5; int gcd(int x, int y) { while (x % y) { x %= y; swap(x, y); } return y; } int N; vector<int> adj[MAXN]; int val[MAXN]; long long ans[MAXN]; unordered_map<int, int> freq[MAXN]; void dfs(int pos, int par) { freq[pos][val[pos]] = 1; ans[val[pos]]++; for (int i : adj[pos]) { if (i == par) { continue; } dfs(i, pos); for (const pair<int, int> &p1 : freq[i]) { int newv = gcd(p1.first, val[pos]); for (const pair<int, int> &p2 : freq[pos]) { int g = gcd(newv, p2.first); ans[g] += (long long)p1.second * p2.second; } } for (const pair<int, int> &p1 : freq[i]) { int newv = gcd(p1.first, val[pos]); freq[pos][newv] += p1.second; } freq[i].clear(); } } int main() { cin.tie(0); cin.sync_with_stdio(0); cin >> N; for (int a = 1; a <= N; a++) { cin >> val[a]; } for (int a = 1; a <= N - 1; a++) { int u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } dfs(1, -1); for (int a = 1; a < MAXN; a++) { if (ans[a] != 0) { cout << a << " " << ans[a] << "\n"; } } }
#include <bits/stdc++.h> using namespace std; using ll = long long; const int MX = 2e5 + 1; bool sieve[MX], in_graph[MX], vstd[MX]; vector<int> pos[MX], adj[MX]; int mu[MX]; ll res[MX]; void init() { vector<int> primes; mu[1] = 1; for (int i = 2; i < MX; ++i) { if (!sieve[i]) { mu[i] = -1; primes.push_back(i); } for (auto j : primes) { if (i * j >= MX) break; sieve[i * j] = true; if (i % j == 0) { mu[i * j] = 0; break; } mu[i * j] = -mu[i]; } } } int dfs(int u, int p) { int res = 1; vstd[u] = true; for (auto c : adj[u]) { if (c == p || !in_graph[c]) continue; res += dfs(c, u); } return res; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); init(); int n; cin >> n; for (int i = 1; i <= n; ++i) { int a; cin >> a; for (int j = 1; j * j <= a; ++j) { if (a % j) continue; pos[j].push_back(i); if (a / j != j) { pos[a / j].push_back(i); } } } for (int i = 0; i < n - 1; ++i) { int u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for (int i = 1; i < MX; ++i) { for (auto j : pos[i]) { in_graph[j] = true; } for (auto j : pos[i]) { if (!vstd[j]) { ll cnt = dfs(j, 0); res[i] += cnt * (cnt + 1) / 2; } } for (auto j : pos[i]) { in_graph[j] = false; vstd[j] = false; } } for (int i = 1; i < MX; ++i) { ll ans = 0; for (int j = 1; j * i < MX; ++j) { ans += mu[j] * res[j * i]; } if (ans) { cout << i << ' ' << ans << '\n'; } } }
#include <bits/stdc++.h> using namespace std; inline int gi() { char c; int num = 0, flg = 1; while ((c = getchar()) < '0' || c > '9') if (c == '-') flg = -1; while (c >= '0' && c <= '9') { num = num * 10 + c - 48; c = getchar(); } return num * flg; } int gcd(int x, int y) { return !y ? x : gcd(y, x % y); } vector<pair<int, int> > e[200005]; int a[200005], fa[200005], siz[200005]; int find(int x) { return x == fa[x] ? x : fa[x] = find(fa[x]); } long long ans, f[200005], G[200005]; int prime[200005], tot, mu[200005]; bool vis[200005]; void shai() { int i, j, lim = 200000; vis[1] = 1; mu[1] = 1; for (i = 2; i <= lim; i++) { if (!vis[i]) { prime[++tot] = i; mu[i] = -1; } for (j = 1; j <= tot; j++) { int tmp = i * prime[j]; if (tmp > lim) break; vis[tmp] = 1; if (i % prime[j] == 0) { mu[tmp] = 0; break; } mu[tmp] = -mu[i]; } } } int main() { int n, m = 0, i, j, k, u, v, g, p, q; n = gi(); shai(); for (i = 1; i <= n; i++) a[i] = gi(), m = max(m, a[i]), G[a[i]]++; for (i = 1; i < n; i++) { u = gi(); v = gi(); g = gcd(a[u], a[v]); e[g].push_back(make_pair(u, v)); } for (i = 1; i <= m; i++) { for (j = i; j <= m; j += i) { for (k = 0; k < int(e[j].size()); k++) { u = e[j][k].first; v = e[j][k].second; fa[u] = u; fa[v] = v; siz[u] = siz[v] = 1; } } for (j = i; j <= m; j += i) { for (k = 0; k < int(e[j].size()); k++) { u = e[j][k].first; v = e[j][k].second; p = find(u); q = find(v); if (p != q) { fa[q] = p; f[i] += 1ll * siz[p] * siz[q]; siz[p] += siz[q]; } } } } for (i = 1; i <= m; i++) { for (j = 2 * i; j <= m; j += i) f[i] += f[j] * mu[j / i]; if (f[i] || G[i]) printf("%d %lld\n", i, f[i] + G[i]); } }
#include <bits/stdc++.h> using namespace std; const long long N = 2e5 + 5; long long a[N], n, f[N], mob[N], lst[N], cc, gud[N]; vector<long long> adj[N], idx[N], primes; bitset<N> bs; void sieve() { bs.set(); bs[0] = bs[1] = false; for (long long i = 2; i <= N - 5; ++i) if (bs[i]) { for (long long j = i * i; j <= N - 5; j += i) bs[j] = false; primes.push_back(i); } } long long mobius(long long a) { long long PF_idx = 0, PF = primes[0]; vector<long long> d; d.clear(); while (PF * PF <= a) { long long cnt = 0; while (a % PF == 0) { a /= PF; cnt++; } if (cnt > 1) return 0; if (cnt == 1) d.push_back(PF); PF = primes[++PF_idx]; } if (a) d.push_back(a); if ((long long)d.size() & 1) return -1; else return 1; } long long dfs(long long u, long long val) { long long t = 0; lst[u] = cc; for (long long v : adj[u]) if (gud[a[v]] == cc && lst[v] != cc) t += dfs(v, val); return t + 1; } signed main() { ios_base::sync_with_stdio(0); cin.tie(0); sieve(); cin >> n; for (long long i = 1; i <= n; ++i) { cin >> a[i]; idx[a[i]].push_back(i); } for (long long i = 1; i < n; ++i) { long long u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for (long long i = 1; i <= N - 5; ++i) { ++cc; long long tmp = 0; for (long long j = i; j <= N - 5; j += i) gud[j] = cc; for (long long j = i; j <= N - 5; j += i) { for (long long u : idx[j]) if (lst[u] != cc) { long long sz = dfs(u, i); tmp += sz * (sz + 1) / 2; } } f[i] = tmp; } for (long long i = 1; i <= N - 5; ++i) mob[i] = mobius(i); for (long long i = 1; i <= N - 5; ++i) { long long res = f[i]; for (long long j = 2; j <= (N - 5) / i; j++) res += f[i * j] * mob[j]; if (res > 0) cout << i << ' ' << res << endl; } return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 2e5 + 5; int n, a[maxn], dp[maxn]; vector<int> g[maxn], p[maxn]; set<int> s[maxn]; int dfs(int u, int par, int d) { s[u].insert(d); int res = dp[u] = 1; for (auto v : g[u]) { if (v != par && a[v] % d == 0) { res = max(res, dfs(v, u, d)); res = max(res, dp[u] + dp[v]); dp[u] = max(dp[u], dp[v] + 1); } } return res; } int main() { ios::sync_with_stdio(false); cin.tie(0); cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; int x = a[i]; for (int j = 2; j * j <= x; j++) { if (x % j == 0) { p[i].push_back(j); while (x % j == 0) x /= j; } } if (x > 1) p[i].push_back(x); } for (int i = 1; i <= n - 1; i++) { int x, y; cin >> x >> y; g[x].push_back(y); g[y].push_back(x); } int ans = 0; for (int i = 1; i <= n; i++) { for (auto j : p[i]) { if (s[i].find(j) == s[i].end()) { ans = max(ans, dfs(i, i, j)); } } } cout << ans; return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 200005; int M[maxn]; vector<int> a[maxn]; vector<int> E[maxn]; long long h[maxn]; int maxa = 0; void pre(int maxa) { M[1] = 1; for (int i = 1; i < maxa; i++) { for (int j = i * 2; j <= maxa; j += i) M[j] -= M[i]; } return; } int n; vector<int> now; bool ok[maxn], vis[maxn]; int siz; void dfs(int u) { siz++; vis[u] = 1; for (int i = 0; i < E[u].size(); i++) { if (!vis[E[u][i]] && ok[E[u][i]]) dfs(E[u][i]); } return; } int main() { scanf("%d", &n); for (int i = 1; i <= n; i++) { int q; scanf("%d", &q); a[q].push_back(i); maxa = max(maxa, q); } pre(maxa); for (int i = 1; i < n; i++) { int x, y; scanf("%d%d", &x, &y); E[x].push_back(y); E[y].push_back(x); } for (int i = 1; i <= maxa; i++) { now.clear(); for (int j = i; j <= maxa; j += i) { for (int k = 0; k < a[j].size(); k++) now.push_back(a[j][k]); } for (int j = 0; j < now.size(); j++) ok[now[j]] = 1; for (int j = 0; j < now.size(); j++) { if (!vis[now[j]]) { siz = 0; dfs(now[j]); h[i] += (1LL * siz * (siz + 1) / 2); } } for (int j = 0; j < now.size(); j++) ok[now[j]] = vis[now[j]] = 0; } for (int i = 1; i <= maxa; i++) { long long ans = 0; for (int j = 1; j <= maxa / i; j++) { ans += 1LL * h[j * i] * M[j]; } if (ans != 0) printf("%d %I64d\n", i, ans); } return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXSIZE = 10000020; int bufpos; char buf[MAXSIZE]; void init() { buf[fread(buf, 1, MAXSIZE, stdin)] = '\0'; bufpos = 0; } int readint() { int val = 0; for (; !isdigit(buf[bufpos]); bufpos++) ; for (; isdigit(buf[bufpos]); bufpos++) val = val * 10 + buf[bufpos] - '0'; return val; } char readchar() { for (; isspace(buf[bufpos]); bufpos++) ; return buf[bufpos++]; } int readstr(char* s) { int cur = 0; for (; isspace(buf[bufpos]); bufpos++) ; for (; !isspace(buf[bufpos]); bufpos++) s[cur++] = buf[bufpos]; s[cur] = '\0'; return cur; } const int maxn = 200002; vector<int> v[maxn], e[maxn]; int a[maxn], f[maxn], sz[maxn], fa[maxn]; void dfs(int u) { for (const auto& v : e[u]) { if (fa[u] == v) continue; fa[v] = u; dfs(v); } } bool label[maxn]; long long now; int getf(int x) { return f[x] == x ? x : f[x] = getf(f[x]); } void mer(int x, int y) { x = getf(x), y = getf(y); now += 1LL * sz[x] * sz[y]; f[x] = y; sz[y] += sz[x]; } long long ans[maxn]; int main() { init(); int n = readint(); for (int i = 1; i <= n; i++) f[i] = i, sz[i] = 1; for (int i = 1; i <= n; i++) a[i] = readint(), v[a[i]].push_back(i); for (int i = 1; i < n; i++) { int u = readint(), v = readint(); e[u].push_back(v); e[v].push_back(u); } dfs(1); for (int i = 1; i <= 200000; i++) { now = 0; for (int j = i; j <= 200000; j += i) for (const auto& k : v[j]) { now++; if (fa[k] && a[fa[k]] % i == 0) mer(k, fa[k]); } ans[i] = now; for (int j = i; j <= 200000; j += i) for (const auto& k : v[j]) f[k] = k, sz[k] = 1; } for (int i = 200000; i; i--) for (int j = i * 2; j <= 200000; j += i) ans[i] -= ans[j]; for (int i = 1; i <= 200000; i++) if (ans[i]) printf("%d %lld\n", i, ans[i]); }
#include <bits/stdc++.h> using namespace std; struct node { int v; int nxt; } e[400010]; int n, m, h[200010], cnt, val[200010]; int num[200010][20], dp[200010][20], ans = 1; bool flag = 0; void add(int u, int v) { e[++cnt].v = v; e[cnt].nxt = h[u]; h[u] = cnt; } void work(int pos, int x) { for (int i = 2; i * i <= x; i++) { if (x % i == 0) { num[pos][++num[pos][0]] = i; while (x % i == 0) x /= i; } } if (x > 1) num[pos][++num[pos][0]] = x; } void dfs(int u, int fa) { for (int i = 1; i <= num[u][0]; i++) dp[u][i] = 1; for (int i = h[u]; i; i = e[i].nxt) { int v = e[i].v; if (v == fa) continue; dfs(v, u); for (int j = 1; j <= num[u][0]; j++) { for (int k = 1; k <= num[v][0]; k++) if (num[u][j] == num[v][k]) { ans = max(ans, dp[u][j] + dp[v][k]); dp[u][j] = max(dp[u][j], dp[v][k] + 1); } ans = max(ans, dp[u][j]); } } } int main() { scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &val[i]); if (val[i] > 1) flag = 1; work(i, val[i]); } if (!flag) { printf("0"); return 0; } for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); add(u, v); add(v, u); } dfs(1, 0); printf("%d", ans); }
#include <bits/stdc++.h> using namespace std; template <class A, class B> ostream &operator<<(ostream &out, const pair<A, B> &p) { return out << "(" << p.first << ", " << p.second << ")"; } template <class A> ostream &operator<<(ostream &out, const vector<A> &v) { out << "["; for (auto &e : v) out << e << ", "; return out << "]"; } const int N = 1000 * 1000 + 555; const int LOGN = 21; int mind[N]; int pw[LOGN][N]; int n, a[N]; vector<int> g[N]; long long res[N]; bool gen() { mt19937 rnd(42); n = 200 * 1000; for (int i = int(0); i < int(n); i++) a[i] = 831600; for (int i = int(1); i < int(n); i++) { int u = rnd() % i, v = i; g[u].push_back(v); g[v].push_back(u); } return true; } inline bool read() { if (!(cin >> n)) return false; for (int i = int(0); i < int(n); i++) assert(scanf("%d", &a[i]) == 1); for (int i = int(0); i < int(n - 1); i++) { int u, v; assert(scanf("%d%d", &u, &v) == 2); u--, v--; g[u].push_back(v); g[v].push_back(u); } return true; } vector<pair<int, int> > dv[N]; inline int gcd(int a, int b) { int ans = 1; unsigned int u = 0, v = 0; while (u < dv[a].size() && v < dv[b].size()) { if (dv[a][u].first < dv[b][v].first) u++; else if (dv[a][u].first > dv[b][v].first) v++; else { ans *= pw[min(dv[a][u].second, dv[b][v].second)][dv[a][u].first]; u++, v++; } } return ans; } bool used[N]; int sz[N]; void calcSz(int v, int p) { sz[v] = 1; for (int to : g[v]) { if (to == p || used[to]) continue; calcSz(to, v); sz[v] += sz[to]; } } int findC(int v, int p, int all) { for (int to : g[v]) { if (to == p || used[to]) continue; if (sz[to] > all / 2) return findC(to, v, all); } return v; } int u[N], T = 0; int cntD[N]; inline void addDiv(int d, int cnt) { if (u[d] != T) u[d] = T, cntD[d] = 0; cntD[d] += cnt; } int cds[N], szcds; void calcDs(int v, int p, int gc) { gc = gcd(a[v], gc); cds[szcds++] = gc; for (int to : g[v]) { if (to == p || used[to]) continue; calcDs(to, v, gc); } } vector<int> cps, cmx, vmx; void check(int curd, int curg, int pos, int add) { if (pos >= (int)cps.size()) { if (u[curd] == T) res[curg] += cntD[curd] * 1ll * add; return; } for (int st = int(0); st < int(cmx[pos] + 1); st++) { check(curd, curg, pos + 1, add); curd *= cps[pos]; if (st < vmx[pos]) curg *= cps[pos]; } } pair<int, int> ops[N]; int szops; int cntDiff[N]; void calc(int v) { calcSz(v, -1); int c = findC(v, -1, sz[v]); used[c] = 1; cps.resize(dv[a[c]].size()); cmx.resize(cps.size()); vmx.resize(cmx.size()); for (int i = int(0); i < int(cps.size()); i++) { cps[i] = dv[a[c]][i].first; cmx[i] = dv[a[c]][i].second; } T++; addDiv(a[c], 1); for (int to : g[c]) { if (used[to]) continue; szcds = 0; calcDs(to, c, a[c]); for (int i = int(0); i < int(szcds); i++) cntDiff[cds[i]]++; szops = 0; for (int j = int(0); j < int(szcds); j++) { if (cntDiff[cds[j]] == 0) continue; int p = 0, val = cds[j]; for (int i = int(0); i < int(vmx.size()); i++) { if (p >= (int)dv[val].size() || dv[val][p].first > cps[i]) vmx[i] = 0; else vmx[i] = dv[val][p].second, p++; } check(1, 1, 0, cntDiff[cds[j]]); ops[szops++] = {cds[j], cntDiff[cds[j]]}; cntDiff[cds[j]] = 0; } for (int j = int(0); j < int(szops); j++) addDiv(ops[j].first, ops[j].second); } for (int to : g[c]) { if (used[to]) continue; calc(to); } } inline void solve() { iota(mind, mind + N, 0); for (int i = int(2); i < int(N); i++) { if (mind[i] != i) continue; pw[0][i] = 1; for (int st = int(1); st < int(LOGN); st++) pw[st][i] = pw[st - 1][i] * i; for (long long j = i * 1ll * i; j < N; j += i) mind[j] = min(mind[j], i); } for (int i = int(2); i < int(N); i++) { int val = i; while (mind[val] > 1) { if (dv[i].empty() || dv[i].back().first != mind[val]) dv[i].emplace_back(mind[val], 0); dv[i].back().second++; val /= mind[val]; } } memset(res, 0, sizeof res); T = 0; calc(0); for (int i = int(0); i < int(n); i++) res[a[i]]++; for (int i = int(1); i < int(1000000 + 1); i++) { if (res[i]) cout << i << ' ' << res[i] << endl; } } int main() { if (read()) { solve(); } return 0; }
#include <bits/stdc++.h> using namespace std; int n, m, a[200050]; struct node { int x, y; } ed[200050]; inline int gcd(int a, int b) { return b ? gcd(b, a % b) : a; } vector<int> v[200050]; long long f[200050]; int x[200050], fa[200050], sz[200050]; inline int getfa(int x) { return x == fa[x] ? x : fa[x] = getfa(fa[x]); } inline void merge(int id, int x, int y) { x = getfa(x); y = getfa(y); f[id] += 1ll * sz[x] * sz[y]; fa[x] = y; sz[y] += sz[x]; } bool zhi[200050]; int mu[200050], pri[200050], tot; inline void init(int n) { mu[1] = 1; for (int i = 2; i <= n; ++i) { if (!zhi[i]) pri[++tot] = i, mu[i] = -1; for (int j = 1; j <= tot && 1ll * i * pri[j] <= n; ++j) { zhi[i * pri[j]] = 1; if (!(i % pri[j])) break; mu[i * pri[j]] = -mu[i]; } } } inline void fen(int n) { for (int i = 1; 1ll * i * i <= n; ++i) if (!(n % i)) { ++f[i]; if (i * i != n) ++f[n / i]; } } int main() { scanf("%d", &n); m = 2e5; for (int i = 1; i <= n; ++i) scanf("%d", &a[i]), fen(a[i]), m = max(m, a[i]); init(m); for (int i = 1, gc; i < n; ++i) { scanf("%d%d", &ed[i].x, &ed[i].y); gc = gcd(a[ed[i].x], a[ed[i].y]); for (int j = 1; j * j <= gc; ++j) if (!(gc % j)) { v[j].push_back(i); if (j * j != gc) v[gc / j].push_back(i); } } for (int i = 1; i <= n; ++i) fa[i] = i, sz[i] = 1; for (int i = 1; i <= m; ++i) { for (int j = 0, x, y; j < v[i].size(); ++j) { x = ed[v[i][j]].x; y = ed[v[i][j]].y; merge(i, x, y); } for (int j = 0, x, y; j < v[i].size(); ++j) { x = ed[v[i][j]].x; y = ed[v[i][j]].y; fa[x] = x; sz[x] = 1; fa[y] = y; sz[y] = 1; } } for (int i = 1; i <= m; ++i) { for (int j = 2; 1ll * i * j <= m; ++j) f[i] += mu[j] * f[i * j]; if (f[i]) printf("%d %lld\n", i, f[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; map<int, long long> ans, re, now; int n, h[200005], tot, mp[200005], siz[200005], mz[200005], rem[200005], cnt; bool vis[200005]; struct DX { int v, p; } dx[400005]; int gcd(int a, int b) { return b ? gcd(b, a % b) : a; } void add(int u, int v) { dx[tot].p = h[u]; dx[tot].v = v; h[u] = tot++; } void dfs_G(int u, int fx) { siz[u] = 1; rem[++cnt] = u; mz[u] = 0; for (int i = h[u]; ~i; i = dx[i].p) { int v = dx[i].v; if (v == fx || vis[v]) continue; dfs_G(v, u); siz[u] += siz[v]; mz[u] = max(mz[u], siz[v]); } } int fd_G(int u) { cnt = 0; dfs_G(u, u); for (int i = 1; i <= cnt; i++) if (mz[rem[i]] <= siz[u] / 2 && siz[u] - siz[rem[i]] <= siz[u] / 2) return rem[i]; } void dfs(int u, int fx, int gc) { re[gc = gcd(gc, mp[u])]++; for (int i = h[u]; ~i; i = dx[i].p) { int v = dx[i].v; if (v == fx || vis[v]) continue; dfs(v, u, gc); } } void sol(int u) { u = fd_G(u); vis[u] = 1; now[mp[u]] = 1; ans[mp[u]] += 1; for (int i = h[u]; ~i; i = dx[i].p) { int v = dx[i].v; if (vis[v]) continue; dfs(v, 0, mp[u]); for (map<int, long long>::iterator it = now.begin(); it != now.end(); it++) for (map<int, long long>::iterator ti = re.begin(); ti != re.end(); ti++) ans[gcd(it->first, ti->first)] += it->second * ti->second; for (map<int, long long>::iterator ti = re.begin(); ti != re.end(); ti++) now[ti->first] += ti->second; re.clear(); } now.clear(); for (int i = h[u]; ~i; i = dx[i].p) { int v = dx[i].v; if (vis[v]) continue; sol(v); } } int main() { memset(h, -1, sizeof(h)); scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%d", &mp[i]); int a, b; for (int i = 1; i < n; i++) { scanf("%d%d", &a, &b); add(a, b); add(b, a); } sol(1); for (map<int, long long>::iterator it = ans.begin(); it != ans.end(); it++) printf("%d %lld\n", it->first, it->second); return 0; }
#include <bits/stdc++.h> using namespace std; const int mod = 1e9 + 7; int a[200010], father[200010], fa[200010]; long long size[200010]; vector<int> lis[200010], E[200010]; long long ans[200010]; int find(int x) { if (x == father[x]) return x; return father[x] = find(father[x]); } void DFS(int x, int pre) { for (auto y : E[x]) { if (y == pre) continue; fa[y] = x; DFS(y, x); } } int main() { int n, u, v; scanf("%d", &n); for (int i = 1; i <= n; ++i) scanf("%d", &a[i]), lis[a[i]].push_back(i); for (int i = 1; i < n; ++i) { scanf("%d %d", &u, &v); E[u].push_back(v); E[v].push_back(u); } DFS(1, -1); for (int i = 1; i <= 200000; ++i) { for (int j = i; j <= 200000; j += i) { ans[i] += lis[j].size(); for (auto x : lis[j]) { father[x] = x; size[x] = 1; } } for (int j = i; j <= 200000; j += i) { for (auto x : lis[j]) { if (x == 1) continue; if (father[fa[x]] == 0) continue; int a = find(x), b = find(fa[x]); ans[i] += size[a] * size[b]; father[a] = b, size[b] += size[a]; } } for (int j = i; j <= 200000; j += i) for (auto x : lis[j]) father[x] = size[x] = 0; } for (int i = 200000; i >= 1; --i) { for (int j = 2 * i; j <= 200000; j += i) ans[i] -= ans[j]; } for (int i = 1; i <= 200000; ++i) if (ans[i]) printf("%d %I64d\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; int n, a[200000 + 5], mu[200000 + 5], cc, good[200000 + 5], used[200000 + 5], q[200000 + 5], fr, bk; long long ans1[200000 + 5], ans2[200000 + 5]; vector<int> G[200000 + 5], nbfs[200000 + 5], prime; bool vis[200000 + 5]; void init() { mu[1] = 1; for (int i = 2; i <= 200000; i++) { if (!vis[i]) { prime.push_back(i); mu[i] = -1; } for (int j = 0; i * prime[j] <= 200000; j++) { vis[i * prime[j]] = true; if (i % prime[j] == 0) { mu[i * prime[j]] = 0; break; } mu[i * prime[j]] = -mu[i]; } } } int bfs(int x, int gc) { fr = bk = 0; q[bk++] = x; used[x] = cc; while (fr < bk) { int z = q[fr++]; for (int i = 0; i < G[z].size(); i++) { int y = G[z][i]; if (good[a[y]] == cc && used[y] < cc) { used[y] = cc; q[bk++] = y; } } } return bk; } int main() { init(); scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); nbfs[a[i]].push_back(i); } for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); G[u].push_back(v); G[v].push_back(u); } for (int i = 200000; i > 0; i--) { cc++; for (int j = i; j <= 200000; j += i) good[j] = cc; for (int j = i; j <= 200000; j += i) for (int k = 0; k < nbfs[j].size(); k++) { int x = nbfs[j][k]; if (used[x] == cc) continue; int z = bfs(x, i); ans1[i] += 1ll * z * (z + 1) / 2; } for (int j = i, k = 1; j <= 200000; j += i, k++) ans2[i] += mu[k] * ans1[j]; } for (int i = 1; i <= 200000; i++) if (ans2[i]) printf("%d %lld\n", i, ans2[i]); }
#include <bits/stdc++.h> using namespace std; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); const int N = 2e5 + 100; vector<int> g[N]; int a[N], good[N]; long long ans[N]; int sizes[N], par[N]; vector<int> take[N], vals[N]; int n; int getPar(int v) { if (v == par[v]) return v; return (par[v] = getPar(par[v])); } signed main() { ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0); for (int i = 0; i < N; i++) { par[i] = i; sizes[i] = 1; } cin >> n; for (int i = 0; i < n; i++) { cin >> a[i]; vals[a[i]].push_back(i); } for (int i = 1; i < n; i++) { int v, u; cin >> v >> u; v--; u--; g[v].push_back(u); g[u].push_back(v); } for (int i = 1; i < N; i++) { for (int j = i; j < N; j += i) { take[i].insert(take[i].end(), vals[j].begin(), vals[j].end()); } } for (int i = 1; i < N; i++) { long long cur = 0; for (auto v : take[i]) { good[v] = 1; cur++; } auto get = [&](int x) { return 1ll * x * (x + 1) / 2; }; auto add_edge = [&](int v, int u) { v = getPar(v); u = getPar(u); if (v == u) return; cur -= get(sizes[v]); cur -= get(sizes[u]); if (sizes[v] < sizes[u]) swap(v, u); par[u] = v; sizes[v] += sizes[u]; sizes[u] = 0; cur += get(sizes[v]); }; for (auto v : take[i]) { for (auto u : g[v]) { if (good[u]) { add_edge(v, u); } } } for (auto v : take[i]) { good[v] = 0; par[v] = v; sizes[v] = 1; } ans[i] = cur; } for (int i = N - 1; i >= 1; i--) { for (int j = i + i; j < N; j += i) { ans[i] -= ans[j]; } } for (int i = 1; i < N; i++) { if (ans[i]) { cout << i << ' ' << ans[i] << '\n'; } } }
#include <bits/stdc++.h> using namespace std; #pragma GCC optimize("O3") #pragma GCC target("sse4") const double PI = acos(-1.0); const double EPS = 1e-9; const long long INF = 1e9; const long long LINF = 1e18; const long long mod = 1e9 + 7; const long long MAX = 2e5 + 1; int n; int a[MAX]; vector<int> g[MAX]; long long DP[MAX]; vector<int> vert[MAX]; bool ye[MAX]; bool pozn[MAX]; int marked[MAX]; int counter = 0; int main() { scanf("%d", &n); for (int i = (0); i < (n); ++i) { scanf("%d", &a[i]); vert[a[i]].push_back(i); } int u, v; for (int i = (0); i < (n - 1); ++i) { scanf("%d %d", &u, &v); --u; --v; g[u].push_back(v); g[v].push_back(u); } for (int i = (1); i < (MAX); ++i) { counter = 0; for (int j = i; j < MAX; j += i) { int k; for (int to = (0); to < ((int)((vert[j]).size())); ++to) { k = vert[j][to]; marked[counter++] = k; ye[k] = 1; pozn[k] = 0; } } queue<int> q; long long tut = 0; for (int to = (0); to < (counter); ++to) { int k = marked[to]; if (pozn[k]) continue; q.push(k); pozn[k] = 1; int ye1 = 1; while (!q.empty()) { int t = q.front(); q.pop(); for (int to = (0); to < ((int)((g[t]).size())); ++to) { int su = g[t][to]; if (pozn[su] || ye[su] == 0) continue; pozn[su] = 1; ++ye1; q.push(su); } } tut += ye1 * 1LL * (ye1 - 1) / 2LL; } DP[i] = tut; for (int k = (0); k < (counter); ++k) ye[marked[k]] = 0; } for (int i = (MAX)-1; i >= (1); --i) for (int j = i * 2; j < MAX; j += i) DP[i] -= DP[j]; for (int i = (1); i < (MAX); ++i) DP[i] += (int)((vert[i]).size()); for (int i = (1); i < (MAX); ++i) if (DP[i]) { printf("%d ", i); printf("%lld\n", DP[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; int n; long long a[200100]; vector<int> g[200100]; map<int, long long> m[200100]; long long cnt[200100]; long long gcd(long long x, long long y) { return y == 0 ? x : gcd(y, x % y); } void dfs(int x, int pa) { m[x][a[x]]++; for (int i = 0; i < g[x].size(); i++) { int ver = g[x][i]; if (ver == pa) continue; dfs(ver, x); map<int, long long>::iterator it1, it2; for (it1 = m[x].begin(); it1 != m[x].end(); it1++) { for (it2 = m[ver].begin(); it2 != m[ver].end(); it2++) { cnt[gcd(it1->first, it2->first)] += it1->second * it2->second; } } for (it1 = m[ver].begin(); it1 != m[ver].end(); it1++) { m[x][gcd(a[x], it1->first)] += it1->second; } m[ver].clear(); } } int main() { scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%lld", &a[i]), cnt[a[i]]++; for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); g[u].push_back(v); g[v].push_back(u); } dfs(1, 0); for (int i = 1; i <= 200000; i++) { if (cnt[i]) { printf("%d %lld\n", i, cnt[i]); } } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 3e5 + 500; const long long mod = 1e9 + 7; const long long cmod = 998244353; const long long inf = 1LL << 61; const int M = 1e6 + 500; const long long int ths = 1LL << 40; const int NN = 5e3 + 6; vector<long long int> g[N]; map<long long int, long long int> dp[N]; long long int ans = 0; void dfs(long long int u, long long int p = -1) { for (auto it : g[u]) { if (it != p) { dfs(it, u); } } for (auto &it : dp[u]) { long long int mx1 = 0, mx2 = 0; priority_queue<long long int> pq; for (auto X : g[u]) { if (X == p) { continue; } if (dp[X].count(it.first)) pq.push(dp[X][it.first]); } if (pq.size()) { mx1 = pq.top(); pq.pop(); } if (pq.size()) { mx2 = pq.top(); pq.pop(); } it.second += mx1; ans = max(ans, mx1 + mx2 + 1); } return; } void solve() { long long int n; cin >> n; long long int a[n + 1]; for (int i = 1; i <= n; i++) { cin >> a[i]; if (a[i] == 1) { continue; } while (a[i] % 2 == 0) { a[i] /= 2; dp[i][2] = 1; } for (int j = 3; j * j <= a[i]; j++) { while (a[i] % j == 0) { dp[i][j] = 1; a[i] /= j; } } if (a[i] > 2) { dp[i][a[i]] = 1; } } for (int i = 1; i < n; i++) { long long int x, y; cin >> x >> y; g[x].push_back(y); g[y].push_back(x); } dfs(1); cout << ans; cout << '\n'; return; } int main() { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int t = 1; while (t--) { solve(); } return 0; }
#include <bits/stdc++.h> using namespace std; static inline void canhazfast() { ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); } template <typename T> T gcd(T a, T b) { return b == 0 ? a : gcd(b, a % b); } template <typename T> T extgcd(T a, T b, T &x, T &y) { T x0 = 1, y0 = 0, x1 = 0, y1 = 1; while (b) { T q = a / b; a %= b; swap(a, b); x0 -= q * x1; swap(x0, x1); y0 -= q * y1; swap(y0, y1); } x = x0; y = y0; return a; } static inline int ctz(unsigned x) { return __builtin_ctz(x); } static inline int ctzll(unsigned long long x) { return __builtin_ctzll(x); } static inline int clz(unsigned x) { return __builtin_clz(x); } static inline int clzll(unsigned long long x) { return __builtin_clzll(x); } static inline int popcnt(unsigned x) { return __builtin_popcount(x); } static inline int popcntll(unsigned long long x) { return __builtin_popcountll(x); } static inline int bsr(unsigned x) { return 31 ^ clz(x); } static inline int bsrll(unsigned long long x) { return 63 ^ clzll(x); } unsigned a[200008]; long long ans[200008]; vector<int> adj[200008]; unordered_map<unsigned, long long> cnt[200008]; void dfs(int u, int p = 0) { for (int v : adj[u]) { if (v == p) continue; dfs(v, u); for (auto &cv : cnt[v]) { for (auto &cu : cnt[u]) { ans[gcd(cv.first, cu.first)] += cv.second * cu.second; } } for (auto &cv : cnt[v]) cnt[u][gcd(a[u], cv.first)] += cv.second; cnt[v].clear(); } ++cnt[u][a[u]]; for (auto cu : cnt[u]) ans[cu.first] += cu.second; } int main() { canhazfast(); int n; cin >> n; for (int i = 1; i <= n; ++i) cin >> a[i]; for (int i = 1; i < n; ++i) { int x, y; cin >> x >> y; adj[x].push_back(y); adj[y].push_back(x); } dfs(1); for (int i = 1; i <= 200000; ++i) if (ans[i]) cout << i << ' ' << ans[i] << '\n'; return 0; }
#include <bits/stdc++.h> #pragma warning(disable : 4996) using namespace std; using ld = long double; template <class T> using Table = vector<vector<T>>; const ld eps = 1e-9; template <class S, class T> ostream &operator<<(ostream &os, const pair<S, T> v) { os << "( " << v.first << ", " << v.second << ")"; return os; } template <class T> ostream &operator<<(ostream &os, const vector<T> &v) { for (int i = 0; i < v.size(); i++) { if (i > 0) { os << " "; } os << v[i]; } return os; } template <class T> ostream &operator<<(ostream &os, const vector<vector<T>> &v) { for (int i = 0; i < v.size(); i++) { if (i > 0) { os << endl; } os << v[i]; } return os; } template <class T> ostream &operator<<(ostream &os, const vector<set<T>> &v) { for (int i = 0; i < v.size(); i++) { if (i > 0) { os << endl; } os << v[i]; } return os; } template <class T> ostream &operator<<(ostream &os, const set<T> &v) { int i = 0; for (auto it : v) { if (i > 0) { os << ' '; } os << it; i++; } return os; } using ll = long long int; const int MAX_N = 2e5; vector<int> min_divs(MAX_N + 1); void init() { iota(min_divs.begin(), min_divs.end(), 0); for (ll x = 2; x <= MAX_N; ++x) { if (min_divs[x] == x) { for (int y = x * x; y <= MAX_N; y += x) { if (min_divs[y] == y) { min_divs[y] = x; } } } } } ll bfs(int start, const vector<vector<int>> &edges, vector<int> &oks) { assert(oks[start] == true); int sum = 0; queue<int> que; que.push(start); while (!que.empty()) { int now = que.front(); que.pop(); oks[now] = false; sum++; for (auto e : edges[now]) { if (oks[e]) que.emplace(e); } } return sum; } int main() { ios::sync_with_stdio(false); int N; cin >> N; vector<int> v(N); for (int i = 0; i < N; ++i) cin >> v[i]; vector<vector<int>> ids(MAX_N + 1); for (int i = 0; i < N; ++i) ids[v[i]].push_back(i); vector<vector<int>> edges(N); for (int i = 0; i < N - 1; ++i) { int a, b; cin >> a >> b; a--; b--; edges[a].push_back(b); edges[b].push_back(a); } vector<ll> anss(MAX_N + 1); vector<int> oks(N); for (int num = 1; num <= MAX_N; ++num) { vector<int> now_ids; for (int x = num; x <= MAX_N; x += num) { for (auto id : ids[x]) { oks[id] = true; now_ids.push_back(id); } } ll nanswer = 0; for (auto n_id : now_ids) { if (oks[n_id]) { ll sum = bfs(n_id, edges, oks); nanswer += sum * (sum + 1) / 2; } } anss[num] = nanswer; } for (int num = MAX_N; num >= 1; --num) { for (int x = 2 * num; x <= MAX_N; x += num) { anss[num] -= anss[x]; } } for (int num = 1; num <= MAX_N; ++num) { if (anss[num]) { cout << num << ' ' << anss[num] << endl; } } return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 10; const int MAXN = 200000; int n, tot; bool bz[N]; vector<int> g[N], edge[N]; int e[N * 2][2], gg[N]; int sz; long long ans[N]; void add(int x, int y) { e[++tot][0] = y; e[tot][1] = gg[x]; gg[x] = tot; } void dfs(int x) { bz[x] = 0; sz++; for (int i = gg[x]; i; i = e[i][1]) if (bz[e[i][0]]) dfs(e[i][0]); gg[x] = 0; } int main() { scanf("%d", &n); for (int i = 1; i <= n; i++) { int x; scanf("%d", &x); for (int j = 1; 1ll * j * j <= x; j++) if ((x % j) == 0) { g[j].push_back(i); if (j * j != x) g[x / j].push_back(i); } } for (int i = 1; i < n; i++) { int x, y; scanf("%d %d", &x, &y); edge[x].push_back(y); edge[y].push_back(x); } for (int i = 1; i <= MAXN; i++) if (g[i].size()) { tot = 0; for (auto u : g[i]) bz[u] = 1; for (auto u : g[i]) for (auto v : edge[u]) if (bz[v]) add(u, v); for (auto u : g[i]) if (bz[u]) { sz = 0; dfs(u); ans[i] += 1ll * sz * (sz - 1) / 2 + sz; } } for (int i = MAXN; i; i--) for (int j = 2; 1ll * j * i <= MAXN; j++) ans[i] -= ans[i * j]; for (int i = 1; i <= MAXN; i++) if (ans[i]) printf("%d %lld\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 200010; int n, a[MAXN], u[MAXN], v[MAXN]; int gcd(int a, int b) { return b ? gcd(b, a % b) : a; } vector<int> c[MAXN]; long long f[MAXN]; int x[MAXN], fa[MAXN], siz[MAXN]; int getfa(int u) { return u == fa[u] ? u : fa[u] = getfa(fa[u]); } inline void merge(int j, int u, int v) { u = getfa(u); v = getfa(v); if (u == v) return; f[j] += (long long)siz[u] * siz[v]; fa[u] = v; siz[v] += siz[u]; } int mu[MAXN], prm[MAXN], pn; bool notp[MAXN]; void table(int n) { notp[0] = notp[1] = 1; mu[1] = 1; for (int i = 2; i <= n; i++) { if (!notp[i]) { prm[++pn] = i; mu[i] = -1; } for (int j = 1; j <= pn && prm[j] * i <= n; j++) { notp[prm[j] * i] = 1; if (i % prm[j]) mu[prm[j] * i] = -mu[i]; else { mu[prm[j] * i] = 0; break; } } } } int main() { cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; for (int j = 1; j * j <= a[i]; j++) if (!(a[i] % j)) { f[j]++; if (j * j != a[i]) ++f[a[i] / j]; } } for (int i = 1; i < n; i++) { cin >> u[i] >> v[i]; int t = gcd(a[u[i]], a[v[i]]); for (int j = 1; j * j <= t; j++) if (!(t % j)) { c[j].push_back(i); if (j * j != t) c[t / j].push_back(i); } } int m = 200000; for (int i = 1; i <= m; i++) { for (int j = 0; j < c[i].size(); j++) { fa[u[c[i][j]]] = u[c[i][j]]; siz[u[c[i][j]]] = 1; fa[v[c[i][j]]] = v[c[i][j]]; siz[v[c[i][j]]] = 1; } for (int j = 0; j < c[i].size(); j++) merge(i, u[c[i][j]], v[c[i][j]]); } table(m); for (int k = 1; k <= m; k++) { long long ans = 0; for (int i = 1; i * k <= m; i++) ans += mu[i] * f[i * k]; if (ans) cout << k << ' ' << ans << '\n'; } return 0; }
#include <bits/stdc++.h> using namespace std; inline int readInt() { char c; int tmp = 0, x = 1; c = getchar(); while (c > '9' || c < '0') { if (c == '-') x = -1; c = getchar(); } while (c >= '0' && c <= '9') { tmp = tmp * 10 + c - '0'; c = getchar(); } return tmp * x; } const int maxN = 200000 + 10; int a[maxN], n; vector<int> g[maxN]; void addEdge(int u, int v) { g[u].push_back(v); g[v].push_back(u); } bool vis[maxN]; int pri[maxN], tot = 0, mu[maxN]; void sieve() { mu[1] = 1; for (int i = 2; i < maxN; i++) { if (!vis[i]) pri[++tot] = i, mu[i] = -1; for (int j = 1; j <= tot && pri[j] * i < maxN; j++) { vis[pri[j] * i] = true; if (i % pri[j] == 0) { mu[pri[j] * i] = 0; break; } mu[pri[j] * i] = -mu[i]; } } } int Fa[maxN]; void dfs(int v, int fa) { Fa[v] = fa; for (int i = 0; i < (int)g[v].size(); i++) { int u = g[v][i]; if (u != fa) dfs(u, v); } } int siz[maxN], f[maxN]; int getFather(int x) { return x == f[x] ? f[x] : f[x] = getFather(f[x]); } void mergeUnion(int u, int v) { int fu = getFather(u), fv = getFather(v); if (fu == fv) return; else { if (siz[fu] > siz[fv]) swap(fu, fv); siz[fv] += siz[fu]; f[fu] = fv; } } vector<int> hav[maxN], all; long long h[maxN], ans[maxN]; int main() { sieve(); memset(vis, 0, sizeof(vis)); n = readInt(); for (int i = 1; i <= n; i++) a[i] = readInt(), hav[a[i]].push_back(i); int u, v; for (int i = 1; i <= n - 1; i++) { u = readInt(), v = readInt(); addEdge(u, v); } dfs(1, -1); for (int i = 1; i <= 200000; i++) { for (int k = 0; k < (int)all.size(); k++) siz[all[k]] = 0, f[all[k]] = 0, vis[all[k]] = false; all.clear(); for (int j = i; j <= 200000; j += i) { for (int k = 0; k < (int)hav[j].size(); k++) { siz[hav[j][k]] = 1, f[hav[j][k]] = hav[j][k]; all.push_back(hav[j][k]); } } for (int k = 0; k < (int)all.size(); k++) { v = all[k]; if (Fa[v] != -1 && a[Fa[v]] % i == 0) mergeUnion(Fa[v], v); } for (int k = 0; k < (int)all.size(); k++) { v = all[k]; if (!vis[u = getFather(v)]) h[i] += 1ll * siz[u] * (siz[u] + 1) / 2, vis[u] = true; } } for (int i = 1; i <= 200000; i++) { for (int j = 1; j <= (200000 / i); j++) { ans[i] += h[j * i] * 1ll * mu[j]; } } for (int i = 1; i <= 200000; i++) { if (ans[i] > 0) printf("%d %I64d\n", i, ans[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; const double pi = 2 * acos(0.0); const int maxn = 2e5 + 10; const int mod = 1e9 + 7; map<int, int> mp[maxn][2]; vector<int> G[maxn]; vector<int> fac[maxn]; int ans = 1; void get_fac(int x, int id) { int n = x; for (int i = 2; i * i <= n; i++) { if (n % i == 0) { while (n % i == 0) n /= i; fac[id].push_back(i); } } if (n != 1) fac[id].push_back(n); } void dfs(int u, int fa) { for (int i = 0; i < fac[u].size(); i++) mp[u][0][fac[u][i]] = 1; for (int i = 0; i < G[u].size(); i++) { int to = G[u][i]; if (to == fa) continue; dfs(to, u); for (int j = 0; j < fac[u].size(); j++) { int nxt = fac[u][j]; int Max = mp[to][0][nxt]; if (Max + 1 > mp[u][0][nxt]) { mp[u][1][nxt] = mp[u][0][nxt]; mp[u][0][nxt] = Max + 1; } else if (Max + 1 == mp[u][0][nxt]) mp[u][1][nxt] = Max + 1; else if (Max + 1 > mp[u][1][nxt]) mp[u][1][nxt] = Max + 1; ans = max(ans, mp[u][0][nxt] + mp[u][1][nxt] - 1); } } } int main() { int n; cin >> n; int flag = 1; for (int i = 1; i <= n; i++) { int x; scanf("%d", &x); if (x != 1) flag = 0; get_fac(x, i); } if (flag) { printf("0\n"); return 0; } for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); G[u].push_back(v); G[v].push_back(u); } dfs(1, 0); printf("%d\n", ans); return 0; }
#include <bits/stdc++.h> using namespace std; int const N = 200000; int n, a[N + 1]; long long an[N + 1]; vector<int> x[N + 1], tr[N + 1]; bool good[N + 1]; int go(int v) { int an = 1; good[v] = false; for (int i = 0; i < (int)(tr[v].size()); ++i) { int u = tr[v][i]; if (!good[u]) continue; an += go(u); } return an; } int main() { scanf("%d", &n); for (int i = 1; i < (int)(n + 1); ++i) scanf("%d", a + i), x[a[i]].push_back(i); for (int i = 1; i < (int)(n); ++i) { int a, b; scanf("%d%d", &a, &b); tr[a].push_back(b); tr[b].push_back(a); } for (int i = 1; i < (int)(N + 1); ++i) { for (int j = i; j <= N; j += i) for (int k = 0; k < (int)(x[j].size()); ++k) good[x[j][k]] = true; for (int j = i; j <= N; j += i) for (int k = 0; k < (int)(x[j].size()); ++k) if (good[x[j][k]]) { int s = go(x[j][k]); an[i] += s + ((long long)s * (s - 1) >> 1); } } for (int i = N; i > 0; --i) for (int j = i << 1; j <= N; j += i) an[i] -= an[j]; for (int i = 1; i < (int)(N + 1); ++i) if (an[i]) printf("%d %lld\n", i, an[i]); }
#include <bits/stdc++.h> using namespace std; int n, a[200000 + 5], mu[200000 + 5], cc, good[200000 + 5], used[200000 + 5], q[200000 + 5], fr, bk; vector<int> G[200000 + 5], nbfs[200000 + 5], prime; long long ans1[200000 + 5], ans2[200000 + 5]; bool vis[200000 + 5]; void init() { mu[1] = 1; for (int i = 2; i <= 200000; i++) { if (!vis[i]) { prime.push_back(i); mu[i] = -1; } for (int j = 0; i * prime[j] <= 200000; j++) { vis[i * prime[j]] = true; if (i % prime[j] == 0) { mu[i * prime[j]] = 0; break; } mu[i * prime[j]] = -mu[i]; } } } int bfs(int x, int gc) { fr = bk = 0; q[bk++] = x; used[x] = cc; while (fr < bk) { int z = q[fr++]; for (int i = 0; i < G[z].size(); i++) { int y = G[z][i]; if (good[a[y]] == cc && used[y] < cc) { used[y] = cc; q[bk++] = y; } } } return bk; } int main() { init(); scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); nbfs[a[i]].push_back(i); } for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); G[u].push_back(v); G[v].push_back(u); } for (int i = 200000; i > 0; i--) { cc++; for (int j = i; j <= 200000; j += i) good[j] = cc; for (int j = i; j <= 200000; j += i) for (int k = 0; k < nbfs[j].size(); k++) { int x = nbfs[j][k]; if (used[x] == cc) continue; int z = bfs(x, i); ans1[i] += 1ll * z * (z + 1) / 2; } for (int j = i, k = 1; j <= 200000; j += i, k++) ans2[i] += mu[k] * ans1[j]; } for (int i = 1; i <= 200000; i++) if (ans2[i]) printf("%d %lld\n", i, ans2[i]); }
#include <bits/stdc++.h> using namespace std; using ll = long long; const int MX = 2e5 + 1; bool sieve[MX], in_graph[MX], vstd[MX]; vector<int> pos[MX], adj[MX]; int mu[MX]; ll res[MX]; void init() { vector<int> primes; mu[1] = 1; for (int i = 2; i < MX; ++i) { if (!sieve[i]) { mu[i] = -1; primes.push_back(i); } for (auto j : primes) { if (i * j >= MX) break; sieve[i * j] = true; if (i % j == 0) { mu[i * j] = 0; break; } mu[i * j] = -mu[i]; } } } int dfs(int u, int p) { int res = 1; vstd[u] = true; for (auto c : adj[u]) { if (c == p || !in_graph[c]) continue; res += dfs(c, u); } return res; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); init(); int n; cin >> n; for (int i = 1; i <= n; ++i) { int a; cin >> a; pos[a].push_back(i); } for (int i = 0; i < n - 1; ++i) { int u, v; cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for (int i = 1; i < MX; ++i) { for (int j = i; j < MX; j += i) { for (auto k : pos[j]) { in_graph[k] = true; } } for (int j = i; j < MX; j += i) { for (auto k : pos[j]) { if (!vstd[k]) { ll cnt = dfs(k, 0); res[i] += cnt * (cnt + 1) / 2; } } } for (int j = i; j < MX; j += i) { for (auto k : pos[j]) { in_graph[k] = false; vstd[k] = false; } } } for (int i = 1; i < MX; ++i) { ll ans = 0; for (int j = 1; j * i < MX; ++j) { ans += mu[j] * res[j * i]; } if (ans) { cout << i << ' ' << ans << '\n'; } } }
#include <bits/stdc++.h> using namespace std; struct Graph { int n; vector<vector<int>> g; Graph(int n) : n(n) { g.resize(n); } void init(int n_) { n = n_; g.resize(n_); } void add_edge(int from, int to) { g[from].push_back(to); } }; struct Tree { int n; int root; vector<vector<int>> t; vector<int> par; vector<int> dpt; void init(Graph &g, int root_) { n = g.n; root = root_; t.resize(n); par.resize(n); dpt.resize(n); fill(dpt.begin(), dpt.end(), -1); queue<int> que; par[root] = -1; dpt[root] = 0; que.push(root); while (que.size()) { int pa = que.front(); que.pop(); for (int ch : g.g[pa]) { if (dpt[ch] == -1) { t[pa].push_back(ch); par[ch] = pa; dpt[ch] = dpt[pa] + 1; que.push(ch); } } } } Tree() {} Tree(Graph &g, int root_) { init(g, root_); } }; int a[200005]; pair<int, int> p[200005]; map<int, int> mp[200005]; int main() { bool pr[500]; vector<int> prime; fill(pr, pr + 500, true); for (int i = 2; i < 500; i++) { if (pr[i]) prime.push_back(i); for (int j = i; j <= 500; j += i) pr[j] = false; } int n; cin >> n; Graph g(n); for (int i = 0; i < n; i++) cin >> a[i]; for (int i = 0; i < n - 1; i++) { int x, y; cin >> x >> y; x--; y--; g.add_edge(x, y); g.add_edge(y, x); } Tree t(g, 0); for (int i = 0; i < n; i++) p[i] = pair<int, int>(t.dpt[i], i); sort(p, p + n, greater<pair<int, int>>()); int ans = 0; for (int c = 0; c < n; c++) { int i = p[c].second; for (int q : prime) { if (a[i] % q == 0) { while (a[i] % q == 0) a[i] /= q; int f = 0, s = 0; for (int ch : t.t[i]) { int x = mp[ch][q]; if (x > f) { s = f; f = x; } else if (x > s) { s = x; } } ans = max(ans, f + s + 1); mp[i][q] = f + 1; } } if (a[i] != 1) { int q = a[i]; int f = 0, s = 0; for (int ch : t.t[i]) { int x = mp[ch][q]; if (x > f) { s = f; f = x; } else if (x > s) { s = x; } } ans = max(ans, f + s + 1); mp[i][q] = f + 1; } } cout << ans << endl; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 9; int n, k; int head[N], nex[2 * N], to[2 * N], now; void add(int a, int b) { to[++now] = b; nex[now] = head[a]; head[a] = now; } int a[N]; long long ans[N]; inline int gcd(int a, int b) { return a == 0 ? b : gcd(b % a, a); } int G; int vis[N]; int siz[N], maxn[N]; void getG(int p, int fa, int sum) { siz[p] = 1; maxn[p] = 0; for (int i = head[p]; ~i; i = nex[i]) { if (!vis[to[i]] && to[i] != fa) { getG(to[i], p, sum); siz[p] += siz[to[i]]; maxn[p] = max(maxn[p], siz[to[i]]); } } maxn[p] = max(maxn[p], sum - siz[p]); if (maxn[G] > maxn[p]) G = p; } int dep[N], num, len[N]; int t1[N], t2[N]; void dfs(int p, int fa) { for (int i = head[p]; ~i; i = nex[i]) { if (vis[to[i]] || fa == to[i]) continue; len[++num] = dep[to[i]] = gcd(dep[p], a[to[i]]); dfs(to[i], p); } } void cal(int p, int mul, int flag) { num = 0; len[++num] = dep[p] = gcd(mul, a[p]); dfs(p, 0); sort(len + 1, len + 1 + num); int ct = 0; for (int i = 1; i <= num; i++) { if (i > 1 && len[i] == len[i - 1]) t2[ct]++; else { t1[++ct] = len[i]; t2[ct] = 1; } } for (int i = 1; i <= ct; i++) { if (t2[i] > 1) { ans[t1[i]] += 1ll * flag * (t2[i] - 1) * t2[i] / 2; } for (int j = i + 1; j <= ct; j++) { ans[gcd(t1[i], t1[j])] += 1ll * flag * t2[i] * t2[j]; } } } void divide(int p) { vis[p] = 1; cal(p, a[p], 1); for (int i = head[p]; ~i; i = nex[i]) { if (vis[to[i]]) continue; cal(to[i], a[p], -1); G = 0; maxn[0] = siz[to[i]]; getG(to[i], 0, siz[to[i]]); divide(G); } } int main() { memset(head, -1, sizeof head); now = 0; int n; scanf("%d", &n); maxn[0] = n; for (int i = 1; i <= n; i++) { scanf("%d", a + i); ans[a[i]]++; } for (int i = 1; i <= n - 1; i++) { int x, y; scanf("%d%d", &x, &y); add(x, y), add(y, x); } G = 0; getG(1, 0, n); divide(G); for (int i = 1; i <= 2e5; i++) { if (ans[i]) { printf("%d %lld\n", i, ans[i]); } } }
#include <bits/stdc++.h> using namespace std; mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); const int N = 2e5 + 100; vector<int> g[N]; int a[N], good[N]; long long ans[N]; int sizes[N], par[N]; vector<int> vals[N]; int n; int getPar(int v) { if (v == par[v]) return v; return (par[v] = getPar(par[v])); } signed main() { ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0); for (int i = 0; i < N; i++) { par[i] = i; sizes[i] = 1; } cin >> n; for (int i = 0; i < n; i++) { cin >> a[i]; vals[a[i]].push_back(i); } for (int i = 1; i < n; i++) { int v, u; cin >> v >> u; v--; u--; g[v].push_back(u); g[u].push_back(v); } for (int i = 1; i < N; i++) { long long cur = 0; for (int j = i; j < N; j += i) { for (auto v : vals[j]) { good[v] = 1; cur++; } } auto get = [&](int x) { return 1ll * x * (x + 1) / 2; }; auto add_edge = [&](int v, int u) { v = getPar(v); u = getPar(u); if (v == u) return; cur -= get(sizes[v]); cur -= get(sizes[u]); if (sizes[v] < sizes[u]) swap(v, u); par[u] = v; sizes[v] += sizes[u]; sizes[u] = 0; cur += get(sizes[v]); }; for (int j = i; j < N; j += i) { for (auto v : vals[j]) { for (auto u : g[v]) { if (good[u]) { add_edge(v, u); } } } } for (int j = i; j < N; j += i) { for (auto v : vals[j]) { good[v] = 0; par[v] = v; sizes[v] = 1; } } ans[i] = cur; } for (int i = N - 1; i >= 1; i--) { for (int j = i + i; j < N; j += i) { ans[i] -= ans[j]; } } for (int i = 1; i < N; i++) { if (ans[i]) { cout << i << ' ' << ans[i] << '\n'; } } }
#include <bits/stdc++.h> using namespace std; const int MAXN = 200005, MAXA = 200000; int n; int mu[MAXN], pri[MAXN], pcnt; bool npr[MAXN]; void sieve() { mu[1] = 1; npr[1] = true; for (int i = 2; i < MAXN; i++) { if (!npr[i]) { pri[++pcnt] = i; mu[i] = -1; } for (int j = 1; j <= pcnt && 1LL * pri[j] * i < MAXN; j++) { npr[i * pri[j]] = true; if (i % pri[j] == 0) { mu[i * pri[j]] = 0; break; } mu[i * pri[j]] = -mu[i]; } } } vector<int> adj[MAXN], node[MAXN]; queue<int> Q; int a[MAXN]; int vis[MAXN]; int bfs(int st, int d) { Q.push(st); vis[st] = d; int ret = 0; while (!Q.empty()) { int u = Q.front(); Q.pop(); ret++; for (int i = 0; i < (int)adj[u].size(); i++) { int v = adj[u][i]; if (vis[v] != d && a[v] % d == 0) { vis[v] = d; Q.push(v); } } } return ret; } long long h[MAXN], ans[MAXN]; int main() { sieve(); int n; scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &a[i]); node[a[i]].push_back(i); } for (int i = 1, x, y; i <= n - 1; i++) { scanf("%d%d", &x, &y); adj[x].push_back(y); adj[y].push_back(x); } for (int i = 1; i <= MAXA; i++) for (int j = i; j <= MAXA; j += i) for (int k = 0; k < (int)node[j].size(); k++) { int st = node[j][k]; if (vis[st] != i) { int sz = bfs(st, i); h[i] += 1LL * sz * (sz + 1LL) / 2LL; } } for (int i = MAXA; i >= 1; i--) for (int j = i, k = 1; j <= MAXA; j += i, k++) ans[i] += mu[k] * h[j]; for (int i = 1; i <= MAXA; i++) if (ans[i]) printf("%d %I64d\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; int ar[200009]; int a[200009]; vector<int> v[200009]; vector<int> ad[200009]; vector<int> v1[200009]; int dp1[200009][7]; int dp2[200009][7]; int ans = 0; void dfs(int x, int p) { int s = ad[x].size(); int i, j, k, l; for (i = 0; i < s; i++) { if (ad[x][i] != p) dfs(ad[x][i], x); } int s1 = v1[x].size(); for (i = 0; i < s1; i++) { int m1 = 0, m2 = 0; for (j = 0; j < s; j++) { if (ad[x][j] == p) continue; int s2 = v1[ad[x][j]].size(); for (k = 0; k < s2; k++) { if (v1[x][i] == v1[ad[x][j]][k]) { if (dp2[ad[x][j]][k] > m1) { m2 = m1; m1 = dp2[ad[x][j]][k]; } else if (dp2[ad[x][j]][k] > m2) m2 = dp2[ad[x][j]][k]; break; } } } dp2[x][i] = 1 + m1; dp1[x][i] = 1 + m1 + m2; ans = max(ans, dp1[x][i]); } } int main() { std::ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); int n, i, j, k, l; for (i = 1; i <= 200000; i++) ar[i] = 1; int maxi = 0; for (i = 2; i <= 200000; i++) { if (ar[i] == 1) { for (j = 1; j * i <= 200000; j++) { v[i * j].push_back(i); int sii = v[i * j].size(); ar[i * j] = 0; maxi = max(maxi, sii); } } } cin >> n; for (i = 1; i <= n; i++) { cin >> a[i]; int si = v[a[i]].size(); for (j = 0; j < si; j++) v1[i].push_back(v[a[i]][j]); } for (i = 1; i <= n - 1; i++) { cin >> j >> k; ad[j].push_back(k); ad[k].push_back(j); } dfs(1, 0); cout << ans; }
#include <bits/stdc++.h> using namespace std; int spf[200005]; set<int> v[200005]; vector<int> g[200005]; int a[200005]; int ans = 0; map<int, int> c[200005]; void sieve() { spf[1] = 1; for (int i = 2; i < 200005; i++) spf[i] = i; for (int i = 4; i < 200005; i += 2) spf[i] = 2; for (int i = 3; i * i < 200005; i++) { if (spf[i] == i) { for (int j = i * i; j < 200005; j += i) if (spf[j] == j) spf[j] = i; } } } void get(int i, int x) { if (x == 0 || x == 1) return; while (x != 1) { v[i].insert(spf[x]); x = x / spf[x]; } } void dfs(int p, int pr) { int i; for (i = 0; i < g[p].size(); i++) { int v1 = g[p][i]; if (v1 != pr) dfs(v1, p); } set<int>::iterator it; for (it = v[a[p]].begin(); it != v[a[p]].end(); it++) { int m = 0; multiset<int> k; k.clear(); for (i = 0; i < g[p].size(); i++) { int v1 = g[p][i]; if (v1 != pr) { if (a[v1] % (*it) == 0) { k.insert(c[v1][*it]), m = max(m, c[v1][*it]); while (k.size() > 2) k.erase(k.begin()); } } } ans = max(ans, m + 1); c[p][*it] = m + 1; if (k.size() == 2) { int x = *k.begin(); ans = max(ans, x + m + 1); } } } int main() { sieve(); int i, j; for (i = 0; i < 200005; i++) v[i].clear(), g[i].clear(), c[i].clear(), get(i, i); int n; cin >> n; for (i = 1; i <= n; i++) cin >> a[i]; for (i = 1; i <= n - 1; i++) { int u, v1; cin >> u >> v1; g[u].push_back(v1); g[v1].push_back(u); } ans = 0; dfs(1, -1); cout << ans; return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 200005; const int maxm = 2 * maxn; const int inf = 0x7fffffff; int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); } struct node { int to, next; } g[maxm]; int n, head[maxn], tol; int a[maxn], prime[maxn][30], ans, dp[maxn][30]; void init() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); }; void add(int x, int y) { g[tol].to = y; g[tol].next = head[x]; head[x] = tol++; } void dfs(int x, int fa) { for (int i = head[x]; i != -1; i = g[i].next) { int id = g[i].to; if (id == fa) continue; dfs(id, x); for (int j = 1; j <= prime[id][0]; j++) { for (int k = 1; k <= prime[x][0]; k++) { if (prime[id][j] == prime[x][k]) { ans = max(ans, dp[x][k] + dp[id][j] + 1); dp[x][k] = max(dp[x][k], dp[id][j] + 1); } } } } } int main() { init(); memset(head, -1, sizeof(head)); tol = 0; cin >> n; for (int i = 1; i <= n; i++) cin >> a[i]; bool flag = 1; for (int i = 1; i <= n; i++) if (a[i] != 1) flag = 0; if (flag) { cout << 0; return 0; } for (int i = 1; i < n; i++) { int x, y; cin >> x >> y; add(x, y); add(y, x); } for (int i = 1; i <= n; i++) { for (int j = 2; j * j <= a[i]; j++) if (a[i] % j == 0) { prime[i][++prime[i][0]] = j; while (a[i] % j == 0) a[i] /= j; } if (a[i] > 1) prime[i][++prime[i][0]] = a[i]; } dfs(1, 1); cout << ans + 1; return 0; }
#include <bits/stdc++.h> using namespace std; void setIO() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); } const int N = 2e5 + 3; const int M = 2e5; const long long inf = 9e17; const long long mod = 1e9 + 7; int xyz = 1; int n, q; int arr[N]; long long vis[N]; long long res[N]; vector<int> fac[N]; vector<int> con[N]; int dfs(int pos, int x) { vis[pos] = 1; for (int adj : con[pos]) if (!vis[adj] && arr[adj] % x == 0) vis[pos] += dfs(adj, x); return vis[pos]; } void red(int x, int p) { for (int i = 1; i * i <= x; i++) { if (x % i) continue; if (i * i == x) { fac[i].push_back(p); } else { fac[i / 1].push_back(p); fac[x / i].push_back(p); } } } void run() { cin >> n; for (int i = 1; i <= n; i++) cin >> arr[i], red(arr[i], i); for (int i = 2; i <= n; i++) { int u; int v; cin >> u >> v; con[u].push_back(v); con[v].push_back(u); } for (int i = 1; i <= M; i++) { for (int x : fac[i]) if (!vis[x]) { long long s = dfs(x, i); res[i] += s * s - s * (s - 1) / 2; } for (int x : fac[i]) vis[x] = 0; } for (int i = M; i >= 1; i--) for (int j = i + i; j <= M; j += i) res[i] -= res[j]; for (int i = 1; i <= M; i++) if (res[i]) cout << i << " " << res[i] << "\n"; } int main() { setIO(); while (xyz--) run(); return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 2e5 + 10, c = 2e5; int n, p[maxn], pri[maxn], mu[maxn], t, vis[maxn], go[maxn], w[maxn], pi = 1, Q[maxn], l, r; long long f[maxn], g[maxn]; vector<int> S[maxn]; struct Edge { Edge* next; int to; Edge(Edge* next = 0, int to = 0) : next(next), to(to) {} } * first[maxn], pool[maxn << 1], *pis = pool; void sieve() { mu[1] = 1; for (int i = 2; i <= c; i++) p[i] = 1; for (int i = 2; i <= c; i++) { if (p[i]) pri[t++] = i, mu[i] = -1; for (int j = 0, d; j < t && (d = i * pri[j]) <= c; j++) { p[d] = 0; if (i % pri[j] == 0) { mu[d] = 0; break; } else mu[d] = -mu[i]; } } } int Bfs(int u) { l = 0, r = 0, Q[++r] = u; vis[u] = pi; while (l < r) { int x = Q[++l]; for (Edge* now = first[x]; now; now = now->next) { if (go[w[now->to]] == pi && (vis[now->to] ^ pi)) { vis[now->to] = pi, Q[++r] = now->to; } } } return r; } int main() { sieve(); scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &w[i]); S[w[i]].push_back(i); } for (int i = 1, u, v; i < n; i++) { scanf("%d%d", &u, &v); first[u] = new (pis++) Edge(first[u], v); first[v] = new (pis++) Edge(first[v], u); } for (int i = c; i; i--, pi++) { for (int j = i; j <= c; j += i) go[j] = pi; for (int j = i; j <= c; j += i) { for (int k = 0; k < S[j].size(); k++) { int u = S[j][k]; if (vis[u] == pi) continue; int x = Bfs(u); g[i] += 1ll * x * (x + 1) >> 1; } } for (int j = i; j <= c; j += i) { f[i] += g[j] * mu[j / i]; } } for (int i = 1; i <= c; i++) if (f[i]) printf("%d %lld\n", i, f[i]); return 0; }
#include <bits/stdc++.h> using namespace std; int in() { int x; scanf("%d", &x); return x; } long long lin() { long long x; scanf("%lld", &x); return x; } const int N = 200010; int n, a[N]; long long ans[N]; vector<int> e[N]; int gcd(int x, int y) { if (y == 0) return x; return gcd(y, x % y); } void dfs(int now, int past, map<int, long long> &mp) { for (int next : e[now]) { if (next == past) continue; map<int, long long> tmp; dfs(next, now, tmp); for (auto p1 : mp) { for (auto p2 : tmp) { ans[gcd(p1.first, p2.first)] += p1.second * p2.second; } } for (auto p : tmp) { mp[gcd(p.first, a[now])] += p.second; } } mp[a[now]]++; for (auto p : mp) { ans[p.first] += p.second; } } int main() { cin >> n; for (int i = 0; i < n; ++i) a[i] = in(); for (int i = 0; i < n - 1; ++i) { int u = in() - 1, v = in() - 1; e[u].push_back(v); e[v].push_back(u); } map<int, long long> mp; dfs(0, -1, mp); for (int i = 1; i <= N - 1; ++i) { if (ans[i] == 0) continue; printf("%d %lld\n", i, ans[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; long long n, i, j, k, l, m, v[201010], q[201001]; vector<long long> qq[201010]; map<long long, long long> c[201010]; long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); } void dfs(long long x, long long p) { c[x][v[x]]++; for (int i = 0; i < qq[x].size(); i++) { long long u = qq[x][i]; if (u == p) { continue; } dfs(u, x); for (map<long long, long long>::iterator it1 = c[x].begin(); it1 != c[x].end(); it1++) { for (map<long long, long long>::iterator it2 = c[u].begin(); it2 != c[u].end(); it2++) { q[gcd(it1->first, it2->first)] += it1->second * it2->second; } } for (map<long long, long long>::iterator it1 = c[u].begin(); it1 != c[u].end(); it1++) { c[x][gcd(it1->first, v[x])] += it1->second; } c[u].clear(); } } int main() { scanf("%lld", &n); for (i = 1; i <= n; i++) { scanf("%lld", &v[i]); q[v[i]]++; } for (i = 1; i <= n - 1; i++) { scanf("%lld%lld", &k, &l); qq[k].push_back(l); qq[l].push_back(k); } dfs(1, 0); for (i = 1; i <= 200000; i++) { if (q[i]) { printf("%lld %lld\n", i, q[i]); } } }
#include <bits/stdc++.h> using namespace std; int a[200010]; vector<int> G[200010]; int S = -1; int idx = -1; void dfs1(int x, int parent, int kind, int depth) { for (auto to : G[x]) { if (parent == to) continue; if (a[to] % kind == 0) dfs1(to, x, kind, depth + 1); } if (S < depth) { S = depth; idx = x; } } int c = 0; int dfs2(int x, int parent, int kind, int depth) { while (a[x] % kind == 0) a[x] /= kind; for (auto to : G[x]) { if (a[to] % kind == 0) dfs2(to, x, kind, depth + 1); } if (parent == -1) return c + 1; c = max(c, depth); return depth; } int main(void) { cin.tie(0); ios::sync_with_stdio(false); int n; cin >> n; for (int i = 0; i < n; i++) cin >> a[i]; for (int i = 0; i < n - 1; i++) { int s, t; cin >> s >> t; s--; t--; G[s].push_back(t); G[t].push_back(s); } int k = 0; for (int j = 2; j * j <= 200000; j++) { for (int i = 0; i < n; i++) { if (a[i] % j == 0) { S = -1; idx = -1; dfs1(i, -1, j, 0); k = max(k, dfs2(idx, -1, j, 0)); } } } for (int i = 0; i < n; i++) { if (a[i] > 1) { S = -1; idx = -1; dfs1(i, -1, a[i], 0); k = max(k, dfs2(idx, -1, a[i], 0)); } } cout << k << endl; return 0; }
#include <bits/stdc++.h> using namespace std; int a[210000]; vector<int> G[210000], F[210000], dp[210000]; void fac(int x) { for (int i = 2; i * i <= a[x]; i++) { if (a[x] % i == 0) { F[x].push_back(i); dp[x].push_back(1); } while (a[x] % i == 0) a[x] /= i; } if (a[x] != 1) { F[x].push_back(a[x]); dp[x].push_back(1); } } void dfs(int u, int f, int& maxn) { for (int i = 0; i < G[u].size(); i++) { int v = G[u][i]; if (v == f) continue; dfs(v, u, maxn); for (int j = 0; j < F[u].size(); j++) { for (int k = 0; k < F[v].size(); k++) { if (F[u][j] == F[v][k]) { maxn = max(maxn, dp[u][j] + dp[v][k]); dp[u][j] = max(dp[u][j], dp[v][k] + 1); } } } } } int main() { ios::sync_with_stdio(false); int n, x, y; while (cin >> n) { bool flg = true; for (int i = 1; i <= n; i++) { F[i].clear(); dp[i].clear(); G[i].clear(); cin >> a[i]; if (a[i] != 1) flg = false; fac(i); } for (int i = 1; i < n; i++) { cin >> x >> y; G[x].push_back(y); G[y].push_back(x); } if (flg) { cout << 0 << endl; continue; } int maxn = 1; dfs(1, 0, maxn); cout << maxn << endl; } return 0; }
#include <bits/stdc++.h> using namespace std; int wei[200005]; vector<int> v[200005]; vector<int> fact[200005]; bool per[200005]; int maxdis; int dfs(int now, int father) { per[now] = 0; int max_child = 1; for (auto i : v[now]) { if (i != father) { if (per[i]) { int val = dfs(i, now); maxdis = max(maxdis, max_child + val); max_child = max(max_child, val + 1); } } } maxdis = max(maxdis, 1); return max_child; } int main() { int n; cin >> n; for (int i = 0; i < n; i++) { cin >> wei[i]; for (int j = 2; j * j <= wei[i]; j++) { if (wei[i] % j == 0) { fact[j].push_back(i); if (wei[i] / j != j) { fact[wei[i] / j].push_back(i); } } } fact[wei[i]].push_back(i); } int a, b; for (int i = 0; i < n - 1; i++) { cin >> a >> b; a--, b--; v[a].push_back(b); v[b].push_back(a); } for (int i = 2; i < 200005; i++) { for (auto j : fact[i]) { per[j] = 1; } for (auto j : fact[i]) dfs(j, -1); } cout << maxdis << endl; }
#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 13; long long dp[MAXN]; int odw[MAXN]; int war[MAXN]; vector<int> v[MAXN]; vector<int> val[MAXN]; int DFS(int x, int licz) { odw[x] = licz; int roz = 1; for (auto it : v[x]) { if (odw[it] != licz && war[it] % licz == 0) roz += DFS(it, licz); } return roz; } int main() { int n; int x, y; long long a; scanf("%d", &n); for (int i = 1; i <= n; i++) { scanf("%d", &x); war[i] = x; for (int j = 1; j * j < x; j++) { if (x % j == 0) { val[j].emplace_back(i); val[x / j].emplace_back(i); } } y = sqrt(x); if (y * y == x) val[y].emplace_back(i); } for (int i = 1; i < n; i++) { scanf("%d %d", &x, &y); v[x].emplace_back(y); v[y].emplace_back(x); } for (int i = 1; i < MAXN; i++) { for (auto it : val[i]) { if (odw[it] != i) { a = DFS(it, i); dp[i] += a * (a + 1) / 2; } } } for (int i = MAXN / 2 - 1; i > 0; i--) { for (int j = i * 2; j < MAXN; j += i) dp[i] -= dp[j]; } for (int i = 1; i < MAXN; i++) { if (dp[i] != 0) printf("%d %lld\n", i, dp[i]); } return 0; }
#include <bits/stdc++.h> const int maxn = 550000; const int INF = 99999999; using namespace std; int v[maxn], head[maxn], ne[maxn], to[maxn]; long long ans[maxn]; int size[maxn], ma[maxn], maxx = -INF; bool vis[maxn]; int n, cnt = 0, root, tot; map<int, long long> temp; map<int, long long> mem; map<int, long long>::iterator iter1; map<int, long long>::iterator iter2; inline int GCD(register int a, register int b) { return a == 0 ? b : GCD(b % a, a); } inline void read(register int &x) { x = 0; register char ch = getchar(); while (ch < '0' || ch > '9') ch = getchar(); while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar(); } inline void add(int f, int t) { ne[++cnt] = head[f], head[f] = cnt, to[cnt] = t; } inline void get_root(int now, int fa) { ma[now] = 0, size[now] = 1; for (register int i = head[now]; i; i = ne[i]) { if (to[i] == fa || vis[to[i]]) continue; get_root(to[i], now); size[now] += size[to[i]]; ma[now] = max(ma[now], size[to[i]]); } ma[now] = max(ma[now], tot - size[now]); if (ma[now] < ma[root]) root = now; } inline void get_dep(int now, int fa, int gcd) { temp[gcd]++; for (register int i = head[now]; i; i = ne[i]) { if (to[i] == fa || vis[to[i]]) continue; get_dep(to[i], now, GCD(gcd, v[to[i]])); } } inline void get_ans(int now) { mem.clear(), mem[v[now]]++, ans[v[now]]++; for (register int i = head[now]; i; i = ne[i]) { if (vis[to[i]]) continue; temp.clear(); get_dep(to[i], now, GCD(v[now], v[to[i]])); for (iter1 = mem.begin(); iter1 != mem.end(); iter1++) { for (iter2 = temp.begin(); iter2 != temp.end(); iter2++) { ans[GCD(iter1->first, iter2->first)] += (long long)(iter1->second) * (iter2->second); } } for (iter1 = temp.begin(); iter1 != temp.end(); iter1++) { mem[iter1->first] += iter1->second; } } } inline void solve(int now) { vis[now] = 1, get_ans(now); for (register int i = head[now]; i; i = ne[i]) { if (vis[to[i]]) continue; tot = size[to[i]], root = 0; get_root(to[i], 0); solve(root); } } int main() { read(n); for (register int i = 1; i <= n; i++) { read(v[i]); maxx = max(maxx, v[i]); } register int f, t; for (register int i = 1; i < n; i++) { read(f), read(t); add(f, t), add(t, f); } size[0] = ma[0] = INF, tot = n; get_root(1, 0); solve(root); for (register int i = 1; i <= maxx; i++) { if (ans[i]) { printf("%d %lld\n", i, ans[i]); } } }
#include <bits/stdc++.h> using namespace std; const int maxn = 2e5 + 10; const int lim = 2e5; vector<int> g[maxn]; long long ans[maxn]; long long a[maxn]; int N; map<int, long long> cnt[maxn]; int gcd(int n, int m) { return n == 0 ? m : gcd(m % n, n); } void DFS(int v, int p) { ++cnt[v][a[v]]; ++ans[a[v]]; for (int u : g[v]) { if (u != p) { DFS(u, v); for (auto& e1 : cnt[v]) { for (auto& e2 : cnt[u]) { ans[gcd(e1.first, e2.first)] += (long long)e1.second * e2.second; } } for (auto& e : cnt[u]) { cnt[v][gcd(a[v], e.first)] += e.second; } cnt[u].clear(); } } } int main() { scanf("%d", &N); for (int i = 1; i <= N; ++i) scanf("%lld", &a[i]); for (int i = 1; i < N; ++i) { int first, second; scanf("%d %d", &first, &second); g[first].push_back(second); g[second].push_back(first); } DFS(1, 1); for (int i = 1; i <= lim; ++i) { if (ans[i]) printf("%d %lld\n", i, ans[i]); } }
#include <bits/stdc++.h> using namespace std; const int MAXN = 2e5 + 1; long long f[MAXN], ans[MAXN]; int par[MAXN], mb[MAXN], sz[MAXN], w[MAXN]; vector<int> di[MAXN], arr[MAXN], adj[MAXN]; inline int qry(int x) { return x == par[x] ? x : par[x] = qry(par[x]); } int main() { for (int i = 2; i * i < MAXN; i++) if (!par[i]) for (int j = i * i; j < MAXN; j += i) par[j] = i; for (int i = 1; i < MAXN; i++) { mb[i] = -1; int j = i; while (j > 0 && par[j] > 0) { if (j % (par[j] * par[j]) == 0) { mb[i] = 0; break; } j /= par[j]; mb[i] *= -1; } for (int j = i; j < MAXN; j += i) di[j].push_back(i); } mb[1] = 1; int n, mx = 0; scanf("%d", &(n)); for (int i = 1; i <= n; i++) { scanf("%d", &(w[i])); for (int j : di[w[i]]) { f[j]++; arr[j].push_back(i); } mx = max(mx, w[i]); } for (int j = 1; j < n; j++) { int u, v; scanf("%d %d", &u, &v); adj[u].push_back(v); adj[v].push_back(u); } for (int i = mx; i > 0; i--) { if (f[i] == 0) continue; for (int j : arr[i]) par[j] = j, sz[j] = 1; for (int j : arr[i]) { int u = qry(j), v; for (int k : adj[j]) { if (w[k] % i != 0 || (v = qry(k)) == u) continue; par[v] = u; f[i] += (long long)sz[u] * (long long)sz[v]; sz[u] += sz[v]; } } for (int j = i, cnt = 1; j <= mx; j += i, cnt++) ans[i] += mb[cnt] * f[j]; } for (int i = 1; i <= mx; i++) if (ans[i]) printf("%d %I64d\n", i, ans[i]); return 0; }
#include <bits/stdc++.h> using namespace std; map<int, long long> c[200018]; vector<int> a[200018]; int n, u, v, val[200018]; long long cnt[200018]; map<int, long long>::iterator it1, it2; inline int read() { int X = 0, w = 1; char ch = 0; while (ch < '0' || ch > '9') { if (ch == '-') w = -1; ch = getchar(); } while (ch >= '0' && ch <= '9') X = (X << 3) + (X << 1) + ch - '0', ch = getchar(); return X * w; } int gcd(int x, int y) { if (y == 0) { return x; } return gcd(y, x % y); } void dfs(int x, int fa) { c[x][val[x]]++; for (int i = (int)a[x].size() - 1; i >= 0; i--) { if (a[x][i] == fa) { continue; } int u = a[x][i]; dfs(u, x); for (it1 = c[x].begin(); it1 != c[x].end(); it1++) { for (it2 = c[u].begin(); it2 != c[u].end(); it2++) { cnt[gcd(it1->first, it2->first)] += it1->second * it2->second; } } for (it1 = c[u].begin(); it1 != c[u].end(); it1++) { c[x][gcd(val[x], it1->first)] += it1->second; } c[u].clear(); } } int main() { n = read(); for (int i = 1; i <= n; i++) { val[i] = read(); cnt[val[i]]++; } for (int i = 1; i < n; i++) { v = read(), u = read(); a[u].push_back(v); a[v].push_back(u); } dfs(1, 0); for (int i = 1; i <= 200000; i++) { if (cnt[i]) { printf("%d %lld\n", i, cnt[i]); } } return 0; }
#include <bits/stdc++.h> using namespace std; vector<long long> adj[200001]; vector<long long> divv[200001]; long long val[200001]; long long ans = 0; vector<long long> path[200001]; void sieve() { for (long long i = 2; i <= 200000; i++) { if (divv[i].size() != 0) continue; for (long long j = i; j <= 200000; j += i) divv[j].push_back(i); } } void dfs(long long node, long long par) { for (long long i = 0; i < adj[node].size(); i++) { if (adj[node][i] != par) dfs(adj[node][i], node); } for (long long i = 0; i < divv[val[node]].size(); i++) { long long maxx = 0, minn = 0; for (long long j = 0; j < adj[node].size(); j++) { if (adj[node][j] == par) continue; long long ind = lower_bound(divv[val[adj[node][j]]].begin(), divv[val[adj[node][j]]].end(), divv[val[node]][i]) - divv[val[adj[node][j]]].begin(); if (val[adj[node][j]] % divv[val[node]][i] == 0) { if (maxx < path[adj[node][j]][ind]) { minn = maxx; maxx = path[adj[node][j]][ind]; } else if (minn < path[adj[node][j]][ind]) minn = path[adj[node][j]][ind]; } } path[node].push_back(1 + maxx); ans = max(ans, maxx + minn + 1); } } int main() { sieve(); long long n; cin >> n; for (long long i = 0; i < n; i++) cin >> val[i]; for (long long i = 0; i < n - 1; i++) { long long x, y; cin >> x >> y; x--; y--; adj[x].push_back(y); adj[y].push_back(x); } dfs(0, -1); cout << ans << endl; return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 10; int a[N], c[N]; vector<int> divs[N]; vector<int> G[N]; vector<int> cnt[N]; long long tot[N], ans[N]; int mu[N], np[N]; void getAns(int n) { for (int i = n; i >= 1; i--) { ans[i] = tot[i]; for (int j = i + i; j <= n; j += i) ans[i] -= ans[j]; } } void dfs(int v, int p = -1) { for (auto u : G[v]) { if (u == p) continue; dfs(u, v); } for (auto x : divs[a[v]]) { c[x] = 1; tot[x]++; } for (auto u : G[v]) { if (u == p) continue; for (int i = 0; i < cnt[u].size(); i++) { int x = divs[a[u]][i]; if (a[v] % x == 0) { tot[x] += (long long)c[x] * cnt[u][i]; c[x] += cnt[u][i]; } } } for (auto x : divs[a[v]]) { cnt[v].push_back(c[x]); c[x] = 0; } } int main() { int n = 200000; for (int i = 1; i <= n; i++) for (int j = i; j <= n; j += i) divs[j].push_back(i); int V; scanf("%d", &V); for (int i = 1; i <= V; i++) { scanf("%d", a + i); } for (int i = 1; i < V; i++) { int u, v; scanf("%d%d", &u, &v); G[u].push_back(v); G[v].push_back(u); } dfs(1); getAns(n); for (int i = 1; i <= n; i++) { if (ans[i] > 0) { printf("%d %lld\n", i, ans[i]); } } }
#include <bits/stdc++.h> using namespace std; int gi() { int a; scanf("%d", &a); return a; } long long gli() { long long a; scanf("%I64d", &a); return a; } int n; vector<int> ne[200000]; vector<int> pr[200000]; int res = 1; bool fn(int a, int b) { return a > b; } void dfs(int a, int parent, map<int, int> &m) { for (int p : pr[a]) m[p] = 1; map<int, vector<int>> q; for (int b : ne[a]) if (b != parent) { map<int, int> mb; dfs(b, a, mb); for (auto &it : mb) if (m.find(it.first) != m.end()) { vector<int> &vec = q[it.first]; vec.push_back(it.second); sort(vec.begin(), vec.end(), fn); if (vec.size() > 2) vec.pop_back(); } } for (auto &it : q) { int alt = it.second[0] + 1; m[it.first] = alt; if (it.second.size() > 1) alt = it.second[0] + it.second[1] + 1; res = (res > alt ? res : alt); } } int main() { n = gi(); int n1 = 1; for (int i = 0; i < n; i++) { int a = gi(); if (a > 1) n1 = 0; for (int p = 2; a > 1 && p * p <= a; p++) if (a % p == 0) { pr[i].push_back(p); while (a % p == 0) a /= p; } if (a) pr[i].push_back(a); } if (n1) { printf("0\n"); return 0; } for (int i = 1; i < n; i++) { int x = gi() - 1; int y = gi() - 1; ne[x].push_back(y); ne[y].push_back(x); } map<int, int> mb; dfs(0, -1, mb); printf("%d\n", res); return 0; }
#include <bits/stdc++.h> using namespace std; int prime[150000]; int lp[200010]; int phi[200010]; class prime_class { public: long top; prime_class() { int i, i2, j; top = 0; lp[0] = 0; lp[1] = 1; for (i = 2; i < 200010; i++) lp[i] = 0; top = 0; for (i = 2; i < 200010; ++i) { if (lp[i] == 0) { lp[i] = i; prime[top++] = i; } for (j = 0; (j < top) && (prime[j] <= lp[i]) && (i * prime[j] < 200010); ++j) lp[i * prime[j]] = prime[j]; } } bool isprime(long long key) { if (key < 200010) return (lp[key] == key) && (key >= 2); else { int i; for (i = 0; (i < top) && (prime[i] * prime[i] <= key); i++) if (key % prime[i] == 0) return false; return true; } } unordered_map<int, int> factorize(int key) { unordered_map<int, int> ans; while (lp[key] != key) { ans[lp[key]]++; key /= lp[key]; } if (key > 1) ans[key]++; return ans; } int get_phi(int key) { int ans = key, last = 0; while (lp[key] != key) { if (lp[key] != last) { last = lp[key]; ans -= ans / last; } key /= lp[key]; } if ((key > 1) && (key != last)) ans -= ans / key; return ans; } void calc_all_phi(int n) { int i, j, k; for (int i = 1; i < n; i++) phi[i] = i; for (int i = 2; i < n; i++) { if (phi[i] == i) { for (int j = i; j < n; j += i) { phi[j] /= i; phi[j] *= i - 1; } } } } vector<pair<long long, long long>> factorize_full(long long key) { vector<pair<long long, long long>> ans; long i, ct, sq = sqrt(key) + 10; for (i = 0; (i < top) && (prime[i] <= sq); i++) if (key % prime[i] == 0) { ct = 0; while (key % prime[i] == 0) { ct++; key /= prime[i]; } ans.push_back({prime[i], ct}); } if (key > 1) { ans.push_back({key, 1}); } return ans; } void generate_divisors(int step, int v, vector<pair<int, int>>& fp, vector<int>& ans) { if (step < fp.size()) { generate_divisors(step + 1, v, fp, ans); for (int i = 1; i <= fp[step].second; i++) { v *= fp[step].first; generate_divisors(step + 1, v, fp, ans); } } else ans.push_back(v); } void generate_divisors_full(long long step, long long v, vector<pair<long long, long long>>& fp, vector<long long>& ans) { if (step < fp.size()) { generate_divisors_full(step + 1, v, fp, ans); for (int i = 1; i <= fp[step].second; i++) { v *= fp[step].first; generate_divisors_full(step + 1, v, fp, ans); } } else ans.push_back(v); } vector<int> get_divisors(int key) { unordered_map<int, int> f = factorize(key); int n = f.size(); vector<pair<int, int>> fp; for (auto p : f) fp.push_back(p); vector<int> ans; generate_divisors(0, 1, fp, ans); return ans; } vector<long long> get_divisors_full(long long key) { vector<pair<long long, long long>> f = factorize_full(key); int n = f.size(); vector<pair<long long, long long>> fp; for (auto p : f) fp.push_back(p); vector<long long> ans; generate_divisors_full(0, 1, fp, ans); return ans; } long long get_divisors_count(long long key) { vector<pair<long long, long long>> f = factorize_full(key); long long ans = 1; for (auto p : f) ans *= (p.second + 1); return ans; } }; class UnionFind { private: vector<int> p, rank, setSize; int numSets; public: UnionFind(int N) { setSize.assign(N, 1); numSets = N; rank.assign(N, 0); p.assign(N, 0); for (int i = 0; i < N; i++) p[i] = i; } int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); } bool isSameSet(int i, int j) { return findSet(i) == findSet(j); } void unionSet(int i, int j) { if (!isSameSet(i, j)) { numSets--; int x = findSet(i), y = findSet(j); if (rank[x] > rank[y]) { p[y] = x; setSize[x] += setSize[y]; } else { p[x] = y; setSize[y] += setSize[x]; if (rank[x] == rank[y]) rank[y]++; } } } int numDisjointSets() { return numSets; } int sizeOfSet(int i) { return setSize[findSet(i)]; } }; int main() { ios::sync_with_stdio(false); cin.tie(0); long long n, i, j, k, aa, bb, MAXX = 200010, x, m; prime_class pr; vector<vector<int>> d(MAXX); vector<int> mobius(MAXX); for (i = 1; i < MAXX; i++) d[i] = pr.get_divisors(i); for (i = 1; i < MAXX; i++) { unordered_map<int, int> f = pr.factorize(i); if (f.size() % 2 == 0) mobius[i] = 1; else mobius[i] = -1; for (auto p : f) { if (p.second >= 2) mobius[i] = 0; } } cin >> n; vector<int> a(n + 1); vector<vector<int>> plist(MAXX); for (i = 1; i <= n; i++) { cin >> a[i]; for (auto p : d[a[i]]) plist[p].push_back(i); } vector<vector<int>> adj(n + 1); for (i = 0; i < n - 1; i++) { cin >> aa >> bb; adj[aa].push_back(bb); } vector<int> last(n + 1, -1), cid(n + 1, -1); vector<long long> ans(MAXX, 0), h(MAXX, 0); for (i = 1; i < MAXX; i++) { m = plist[i].size(); for (j = 0; j < m; j++) { int id = plist[i][j]; last[id] = i; cid[id] = j; } UnionFind uf(m); for (j = 0; j < m; j++) { int id = plist[i][j]; for (auto v : adj[id]) { if (last[v] == i) uf.unionSet(j, cid[v]); } } for (j = 0; j < m; j++) { if (uf.findSet(j) == j) { x = uf.sizeOfSet(j); h[i] += x * (x + 1) / 2; } } } for (i = 1; i < MAXX; i++) { x = 0; for (j = i; j < MAXX; j += i) { ++x; if (mobius[x] == 1) ans[i] += h[j]; else if (mobius[x] == -1) ans[i] -= h[j]; } } for (i = 1; i < MAXX; i++) { if (ans[i] > 0) cout << i << " " << ans[i] << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; int n; vector<pair<int, int> > dp[200100]; int val[200100]; vector<vector<int> > g; int res; void ds(int v, int p) { vector<pair<int, int> > ch; for (int i = 0; i < g[v].size(); i++) { if (g[v][i] == p) { continue; } ds(g[v][i], v); for (int j = 0; j < dp[g[v][i]].size(); j++) { ch.push_back(dp[g[v][i]][j]); } } sort(ch.begin(), ch.end()); for (int i = 0; i < ch.size(); i++) { int j = i - 1; int ma = 0, mb = 0; while (ch[j + 1].first == ch[i].first && j + 1 < ch.size()) { j++; int va = ch[j].second; if (va >= ma) { mb = ma; ma = va; } else if (va > mb) { mb = va; } } if (val[v] % ch[j].first == 0) { res = max(res, ma + mb + 1); dp[v].push_back(pair<int, int>(ch[i].first, ma + 1)); while (val[v] % ch[i].first == 0) { val[v] /= ch[i].first; } } else { res = max(res, ma); } i = j; } for (int i = 2; i * i <= val[v]; i++) if (!(val[v] % i)) { dp[v].push_back(pair<int, int>(i, 1)); res = max(res, 1); while (!(val[v] % i)) { val[v] /= i; } } if (val[v] > 1) { dp[v].push_back(pair<int, int>(val[v], 1)); res = max(res, 1); } } int main() { scanf("%d ", &n); for (int i = 0; i < n; i++) { int t; scanf("%d ", &t); val[i] = t; } g.assign(n, vector<int>()); for (int i = 0; i < n - 1; i++) { int a, b; scanf("%d %d ", &a, &b); a--; b--; g[b].push_back(a); g[a].push_back(b); } res = 0; ds(0, -1); printf("%d\n", res); }
#include <bits/stdc++.h> #pragma comment(linker, "/stack:200000000") #pragma GCC optimize("Ofast") #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") using namespace std; const long inf = 1e9 + 7; const long N = 2e5 + 5; long A[N], n, k, vis[N], c; vector<long> adj[N], v[N]; long long dp[N]; void dfs(long id, long p, long num) { c++; vis[id] = num; for (auto i : adj[id]) if (i != p && A[i] % num == 0) dfs(i, id, num); } void solve() { long i, j, x = 0, y = 1, m, a, b; cin >> n; for (i = 1; i < n + 1; i++) { cin >> A[i]; for (j = 1; j * j < A[i]; j++) { if (A[i] % j == 0) { v[j].emplace_back(i); v[A[i] / j].emplace_back(i); } } if (j * j == A[i]) v[j].emplace_back(i); } for (i = 1; i < n; i++) { cin >> a >> b; adj[a].emplace_back(b); adj[b].emplace_back(a); } for (i = 1; i < N; i++) { for (j = 0; j < (long)v[i].size(); j++) { c = 0; if (vis[v[i][j]] != i) dfs(v[i][j], 0, i); dp[i] += 1LL * c * (c + 1) / 2; } } for (i = N - 1; i > 0; i--) for (j = i + i; j < N; j += i) dp[i] -= dp[j]; for (i = 1; i < N; i++) if (dp[i]) cout << i << " " << dp[i] << "\n"; } signed main() { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); long t = 1, i; while (t--) { solve(); } }
#include <bits/stdc++.h> using namespace std; int n, mx = 0; int res = 0; int a[200001]; vector<int> tree[200001]; vector<int> prime; vector<int> app[200001]; int dv[200001]; int o[200001]; int mdown[200001]; vector<int> mults[200001]; int DFS(int v, int p, int it) { o[v] = it; int m1 = 0, m2 = 0, l = 0, d; for (size_t i = 0; i < tree[v].size(); i++) { if (o[tree[v][i]] != it && a[tree[v][i]] % p == 0) { l = max(l, DFS(tree[v][i], p, it)); d = mdown[tree[v][i]]; if (d > m1) { m2 = m1; m1 = d; } else if (d > m2) m2 = d; } } mdown[v] = 1 + m1; return max(l, 1 + m1 + m2); } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; app[a[i]].push_back(i); mx = max(mx, a[i]); } int x, y; for (int i = 0; i < n - 1; i++) { cin >> x >> y; tree[x].push_back(y); tree[y].push_back(x); } for (int i = 2; i * i <= mx; i++) { if (!dv[i]) { for (int j = i * i; j <= mx; j += i) { dv[j] = i; } } } for (int i = 2; i <= mx; i++) { if (!dv[i]) { prime.push_back(i); } } for (int i = 2; i <= mx; i++) { int a1 = i; while (dv[a1] > 0) { if (!mults[dv[a1]].size() || mults[dv[a1]].back() != i) { mults[dv[a1]].push_back(i); } a1 /= dv[a1]; } if (a1 > 1 && (!mults[a1].size() || mults[a1].back() != i)) { mults[a1].push_back(i); } } for (int i = 0; i < (int)prime.size(); i++) { for (int j = 0; j < (int)mults[prime[i]].size(); j++) { int j2 = mults[prime[i]][j]; for (int k = 0; k < (int)app[j2].size(); k++) { if (o[app[j2][k]] != i + 1) { res = max(res, DFS(app[j2][k], prime[i], i + 1)); } } } } cout << res; return 0; }
#include <bits/stdc++.h> const int maxn = 2e5 + 10; const int mod = 998244353; 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 T1, typename T2> void addmo(T1 &a, T2 b) { a += b; if (a >= mod) a -= mod; } int n, a[maxn], vis[maxn], sz[maxn], mx[maxn], mi, o, ans, mx1, mx2, mxx; vector<int> g[maxn]; void dfs_size(int x, int pre) { sz[x] = 1, mx[x] = 0; for (int i : g[x]) if (!vis[i] && pre ^ i) dfs_size(i, x), sz[x] += sz[i], mx[x] = max(mx[x], sz[i]); } void dfs_findG(int r, int x, int pre) { if (sz[r] - sz[x] > mx[x]) mx[x] = sz[r] - sz[x]; if (mx[x] < mi) mi = mx[x], o = x; for (int i : g[x]) if (i ^ pre && !vis[i]) dfs_findG(r, i, x); } void dfs_dis(int x, int pre, int dep, int val) { ckmax(mxx, dep); for (int i : g[x]) if (!vis[i] && i ^ pre && a[i] % val == 0) dfs_dis(i, x, dep + 1, val); } void cal(int x, int val) { mx1 = 0, mx2 = 0; for (int i : g[x]) { if (!vis[i] && a[i] % val == 0) { mxx = 0; dfs_dis(i, x, 1, val); if (mx1 < mxx) mx2 = mx1, mx1 = mxx; else if (mx2 < mxx) mx2 = mxx; } } ckmax(ans, mx1 + mx2 + 1); } void dfs(int x) { mi = 0x3f3f3f3f; dfs_size(x, 0); dfs_findG(x, x, 0); vis[o] = 1; int rt = o, val = a[o]; for (int i = 2; i * i <= val; i++) { if (val % i == 0) { cal(o, i); while (val % i == 0) val /= i; } } if (val > 1) cal(o, val); for (int i : g[rt]) if (!vis[i]) dfs(i); } void solve() { int f = 1; scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%d", &a[i]), f &= a[i] == 1; for (int i = 1, x, y; i < n; i++) { scanf("%d%d", &x, &y); g[x].push_back(y), g[y].push_back(x); } dfs(1); printf("%d", ans); } signed main() { solve(); return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> void read(T &x) { x = 0; int f = 1; char ch = getchar(); while (ch < '0' || ch > '9') { if (ch == '-') f = -1; ch = getchar(); } while (ch >= '0' && ch <= '9') x = (x << 3) + (x << 1) + ch - '0', ch = getchar(); x *= f; } struct edge { int to, v, next; } e[400005]; int n, m, p, val[200005], head[200005], cnt, siz[200005], son[200005], st[200005], top, root, maxson, vis[200005], dis[200005]; long long tot[200005], ma[200005]; void add(int a, int b) { e[cnt].to = b; e[cnt].next = head[a]; head[a] = cnt++; } void getroot(int u, int pre) { siz[u] = 1; son[u] = 0; for (register int i = head[u]; i; i = e[i].next) { if (e[i].to == pre || vis[e[i].to]) continue; getroot(e[i].to, u); siz[u] += siz[e[i].to]; son[u] = max(son[u], siz[e[i].to]); } son[u] = max(son[u], maxson - siz[u]); if (son[u] < son[root]) root = u; } int gcd(int a, int b) { if (a % b == 0) return b; return gcd(b, a % b); } void getans(int u, int pre) { dis[u] = gcd(dis[pre], val[u]); for (register int i = 1; i <= top; ++i) { tot[gcd(dis[u], st[i])] += ma[st[i]]; } for (register int i = head[u]; i; i = e[i].next) { if (e[i].to == pre || vis[e[i].to]) continue; getans(e[i].to, u); } } void getdis(int u, int pre) { if (!ma[dis[u]]) { st[++top] = dis[u]; } ma[dis[u]]++; for (register int i = head[u]; i; i = e[i].next) { if (e[i].to == pre || vis[e[i].to]) continue; getdis(e[i].to, u); } } void calc(int u) { tot[val[u]]++; top = 1; dis[u] = val[u]; ma[val[u]] = 1; st[1] = val[u]; for (register int i = head[u]; i; i = e[i].next) { if (vis[e[i].to]) continue; getans(e[i].to, u); getdis(e[i].to, u); } for (register int i = 1; i <= top; ++i) { ma[st[i]] = 0; } } void dfs(int u) { calc(u); vis[u] = 1; for (register int i = head[u]; i; i = e[i].next) { if (vis[e[i].to]) continue; root = 0; maxson = siz[e[i].to]; getroot(e[i].to, u); dfs(root); } } int main() { read(n); cnt = 1; for (register int i = 1; i <= n; ++i) read(val[i]); int a, b; for (register int i = 1; i < n; ++i) { read(a); read(b); add(a, b); add(b, a); } maxson = siz[0] = son[0] = n; root = 0; getroot(1, 0); dfs(root); for (register int i = 1; i <= 200000; ++i) { if (tot[i]) printf("%d %lld\n", i, tot[i]); } }
#include <bits/stdc++.h> using namespace std; const long long mx = 200000; vector<long long> val[mx + 1]; vector<pair<long long, long long>> tr[mx + 1]; long long gcd(long long a, long long b) { while (b) tie(a, b) = make_tuple(b, a % b); return a; } template <typename t> class DisjointSet { public: vector<t> dsu, SIZE; DisjointSet(t n) { dsu.resize(n + 1); SIZE.assign(n + 1, 1); iota(dsu.begin(), dsu.end(), 0); } t root(t a) { return dsu[a] == a ? a : dsu[a] = root(dsu[a]); } void join(t a, t b, t &res) { a = root(a); b = root(b); if (a == b) return; res -= (SIZE[a] * (SIZE[a] + 1) >> 1); res -= (SIZE[b] * (SIZE[b] + 1) >> 1); if (SIZE[a] < SIZE[b]) dsu[a] = b, SIZE[b] += SIZE[a], res += (SIZE[b] * (SIZE[b] + 1) >> 1); else dsu[b] = a, SIZE[a] += SIZE[b], res += (SIZE[a] * (SIZE[a] + 1) >> 1); } }; void solve() { long long n, x, y; cin >> n; long long a[n + 1], res[mx + 1]; memset(res, 0, sizeof res); DisjointSet<long long> tree(n); for (long long i = 1; i <= n; i++) cin >> a[i], val[a[i]].push_back(i); for (long long i = 1; i < n; i++) cin >> x >> y, tr[(gcd(a[x], a[y]))].push_back({x, y}); for (long long i = mx; i > 0; i--) { res[i] = 0; for (long long j = i; j <= mx; j += i) { res[i] -= res[j]; res[i] += val[j].size(); for (auto &k : val[j]) tree.dsu[k] = k, tree.SIZE[k] = 1; } for (long long j = i; j <= mx; j += i) for (auto &k : tr[j]) tree.join(k.first, k.second, res[i]); } for (long long i = 1; i <= mx; i++) if (res[i] > 0) cout << i << " " << res[i] << "\n"; } signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); long long t(1); for (long long i = 1; i <= t; solve(), i++) ; return 0; }
#include <bits/stdc++.h> using namespace std; namespace Fread { const long long MAXN = 1 << 20; char buf[MAXN], *S, *T; inline char getchar() { if (S == T) { T = (S = buf) + fread(buf, 1, MAXN, stdin); if (S == T) return EOF; } return *S++; } } // namespace Fread inline long long read() { long long x(0), neg(1); char ch = getchar(); while (!isdigit(ch)) { if (ch == '-') neg = -1; ch = getchar(); } while (isdigit(ch)) { x = (x << 1) + (x << 3) + (ch - '0'); ch = getchar(); } return x * neg; } const long long MAXN = 2e5; vector<long long> pri[MAXN + 5]; vector<long long> g[MAXN + 5]; long long dp[MAXN + 5][10]; long long ans; inline void dfs(long long u, long long fa) { for (long long i = 0; i < g[u].size(); ++i) { long long v(g[u][i]); if (v == fa) continue; dfs(v, u); for (long long j = 0; j < pri[u].size(); ++j) { for (long long k = 0; k < pri[v].size(); ++k) { if (pri[u][j] != pri[v][k]) continue; ans = max(ans, dp[u][j] + dp[v][k] + 1); dp[u][j] = max(dp[u][j], dp[v][k] + 1); } } } } long long num[MAXN + 5]; long long p[MAXN + 5], prime[MAXN + 5]; long long cnt; inline void PRIME(long long x) { memset(prime, 1, sizeof(prime)); prime[0] = prime[1] = 0; for (long long i = 2; i <= x; ++i) { if (prime[i]) p[++cnt] = i; for (long long j = 1; j <= cnt && p[j] * i <= x; ++j) { prime[p[j] * i] = 0; if (i % p[j] == 0) break; } } } signed main() { long long n = read(); long long flag = 1; for (long long i = 1; i <= n; ++i) { num[i] = read(); if (num[i] != 1) flag = 0; } if (flag) { puts("0"); return 0; } for (long long i = 1; i < n; ++i) { long long u(read()), v(read()); g[u].push_back(v), g[v].push_back(u); } PRIME(200000); for (long long i = 1; i <= n; ++i) { long long tmp = num[i]; for (long long j = 1; p[j] * p[j] <= tmp; ++j) { if (tmp <= 1) break; if (tmp % p[j] == 0) { pri[i].push_back(p[j]); while (tmp % p[j] == 0) { tmp /= p[j]; } } } if (tmp != 1) pri[i].push_back(tmp); } dfs(1, 0); printf("%lld\n", ans + 1); return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 2e5 + 5; vector<int> v[maxn], g[maxn]; int a[maxn], dv[maxn], fd, fr; bool vis[maxn]; void dfs(int x, int y, int p, int d) { vis[x] = true; if (d > fd) { fd = d; fr = x; } for (const int &u : g[x]) { if (u == p) continue; if (a[u] % y) continue; dfs(u, y, x, d + 1); } } void sieve() { vector<int> p; for (int i = 2; i < maxn; ++i) { if (!dv[i]) dv[i] = i, p.push_back(i); for (int j = 0; i * p[j] < maxn; ++j) { dv[i * p[j]] = p[j]; if (i % p[j] == 0) break; } } } vector<int> fact(int x) { vector<int> res; for (int y = x; y < maxn; y += x) { for (int i = 0; i < (int)v[y].size(); ++i) res.push_back(v[y][i]); } return res; } int main() { sieve(); int n; scanf("%d", &n); for (int i = 0; i < n; ++i) { scanf("%d", &a[i]); v[a[i]].push_back(i); } for (int i = 0; i < n - 1; ++i) { int x, y; scanf("%d%d", &x, &y); --x, --y; g[x].push_back(y); g[y].push_back(x); } int ans = 0; for (int i = 2; i < maxn; ++i) { if (dv[i] != i) continue; vector<int> p = fact(i); for (int j = 0; j < (int)p.size(); ++j) { int x = p[j]; if (vis[x]) continue; fd = fr = -1; dfs(x, i, -1, 1); fd = -1; dfs(fr, i, -1, 1); ans = max(ans, fd); } for (int j = 0; j < (int)p.size(); ++j) { int x = p[j]; vis[x] = false; } } printf("%d\n", ans); return 0; }
#include <bits/stdc++.h> using namespace std; int n, a[200005], ans; vector<int> g[200005], t[200005]; map<int, int> dp[200005], mx[200005], mx2[200005]; map<int, int>::iterator it; void dfs(int node, int par) { for (int i = 0; i < g[node].size(); i++) { if (g[node][i] == par) continue; dfs(g[node][i], node); } for (int i = 0; i < t[a[node]].size(); i++) dp[node][t[a[node]][i]] = 1; for (int i = 0; i < g[node].size(); i++) { if (g[node][i] == par) continue; for (it = dp[g[node][i]].begin(); it != dp[g[node][i]].end(); it++) { if (a[node] % it->first == 0) { dp[node][it->first] = max(dp[node][it->first], it->second + 1); mx2[node][it->first] = max(mx2[node][it->first], it->second); if (mx2[node][it->first] > mx[node][it->first]) swap(mx2[node][it->first], mx[node][it->first]); ans = max(ans, mx[node][it->first] + mx2[node][it->first] + 1); } else { ans = max(ans, it->second); } } dp[g[node][i]].clear(); } } int main() { for (int i = 2; i < 200005; i++) if (t[i].empty()) for (int j = i; j < 200005; j += i) t[j].push_back(i); scanf("%d", &n); for (int i = 1; i <= n; i++) scanf("%d", a + i); if (n == 1) { printf("%d\n", a[1] > 1); return 0; } for (int i = 1; i < n; i++) { int u, v; scanf("%d %d", &u, &v); g[u].push_back(v); g[v].push_back(u); } dfs(1, 0); printf("%d\n", ans); return 0; }
#include <bits/stdc++.h> using namespace std; inline int rf() { int r; int s = 0, c; for (; !isdigit(c = getchar()); s = c) ; for (r = c ^ 48; isdigit(c = getchar()); (r *= 10) += c ^ 48) ; return s ^ 45 ? r : -r; } vector<int> e[200000 + 5], pr[200000 + 5], ver[200000 + 5]; bool book[200000 + 5]; int a[200000 + 5], fa[200000 + 5], n, m, D, V, ans; void Far(int p, int fa, int t) { book[p] = false; D < t ? D = t, V = p : 0; for (auto v : e[p]) if (v ^ fa) Far(v, p, t + 1); } void DFS(int p) { for (auto v : e[p]) if (v ^ fa[p]) fa[v] = p, DFS(v); } int main() { n = rf(); generate(a + 1, a + n + 1, rf); m = *max_element(a + 1, a + n + 1); for (register int i = 2, j; i <= m; i++) if (!book[i]) for (j = i; j <= m; book[j] = true, pr[j].push_back(i), j += i) ; for (register int i = 2, u, v; i <= n; u = rf(), v = rf(), e[u].push_back(v), e[v].push_back(u), i++) ; for (register int i = 1; i <= n; i++) for (auto j : pr[a[i]]) ver[j].push_back(i); DFS(1); memset(book, 0, m); for (register int i = 2; i <= m; i++) if (ver[i].size()) { for (auto v : ver[i]) book[v] = true, e[v].clear(); for (auto v : ver[i]) if (book[fa[v]]) e[v].push_back(fa[v]), e[fa[v]].push_back(v); for (auto v : ver[i]) if (book[v]) D = 1, V = v, Far(v, v, 1), Far(V, V, 1), ans = max(ans, D); } printf("%d\n", ans); return 0; }
#include <bits/stdc++.h> using namespace std; using ll = long long; const int MXN = 200005; ll sol[MXN]; int a[MXN], vis[MXN]; vector<int> adj[MXN]; vector<int> ver[MXN]; int dfs(int x, int d) { if (vis[x] == d) return 0; vis[x] = d; int ret = 1; for (int y : adj[x]) { if (a[y] % d) continue; if (vis[y] == d) continue; ret += dfs(y, d); } return ret; } int main() { ios::sync_with_stdio(0), cin.tie(0); int n; cin >> n; for (int i = 1; i <= n; ++i) { cin >> a[i]; ver[a[i]].push_back(i); } for (int i = 2; i <= n; ++i) { int x, y; cin >> x >> y; adj[x].push_back(y); adj[y].push_back(x); } for (int i = 200000; i >= 1; --i) { for (int j = i; j <= 200000; j += i) { sol[i] -= sol[j]; for (int x : ver[j]) { int sz = dfs(x, i); sol[i] += 1LL * sz * (sz + 1) / 2; } } } for (int i = 1; i <= 200000; ++i) { if (sol[i]) cout << i << ' ' << sol[i] << '\n'; } }
#include <bits/stdc++.h> using namespace std; const int N = 200050; vector<int> E[N]; int p[N], sz[N]; long long ans; long long fir(int x) { return (long long)x * (x - 1) / 2; } int Find(int x) { return p[x] == x ? x : p[x] = Find(p[x]); } void Union(int x, int y) { x = Find(x); y = Find(y); ans -= fir(sz[x]); ans -= fir(sz[y]); p[y] = x; sz[x] += sz[y]; ans += fir(sz[x]); } vector<pair<int, int> > edges[N]; int a[N]; long long sol[N]; int gcd(int x, int y) { return x ? gcd(y % x, x) : y; } int main() { int n, i, j, k, u, v; scanf("%i", &n); for (i = 1; i <= n; i++) scanf("%i", &a[i]); for (i = 1; i < n; i++) { scanf("%i %i", &u, &v); edges[gcd(a[u], a[v])].push_back(make_pair(u, v)); } for (i = 1; i < N; i++) { for (j = i; j < N; j += i) { for (k = 0; k < edges[j].size(); k++) { p[edges[j][k].first] = edges[j][k].first; p[edges[j][k].second] = edges[j][k].second; sz[edges[j][k].first] = 1; sz[edges[j][k].second] = 1; } } ans = 0; for (j = i; j < N; j += i) { for (k = 0; k < edges[j].size(); k++) { Union(edges[j][k].first, edges[j][k].second); } } sol[i] = ans; } for (i = 200000; i; i--) { for (j = i * 2; j <= 200000; j += i) sol[i] -= sol[j]; } for (i = 1; i <= n; i++) sol[a[i]]++; for (i = 1; i <= 200000; i++) { if (sol[i]) printf("%i %lld\n", i, sol[i]); } return 0; }
#include <bits/stdc++.h> using namespace std; template <class T> bool umin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } template <class T> bool umax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } const int N = 2e5 + 6; int arr[N]; vector<int> adj[N], mem[N]; long long dp[N]; int ata[N], sz[N], vis[N]; long long all = 0; int tap(int x) { if (ata[x] == x) return x; return ata[x] = tap(ata[x]); } long long f(int x) { return (x * 1LL * (x + 1)) / 2; } void merge(int x, int y) { if ((x = tap(x)) == (y = tap(y))) return; if (sz[x] < sz[y]) swap(x, y); all -= f(sz[x]); all -= f(sz[y]); all += f(sz[x] + sz[y]); sz[x] += sz[y]; ata[y] = x; } int main() { int n; scanf("%d", &n); for (int i = 1; i <= n; i++) { int x; scanf("%d", &x); mem[x].push_back(i); } for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); adj[u].push_back(v); adj[v].push_back(u); } stack<int> st; for (int i = 1; i <= n; i++) ata[i] = i, sz[i] = 1; all = 0; for (int i = N - 4; i >= 1; i--) { for (int j = i; j < N; j += i) { if (i < j) dp[i] -= dp[j]; for (__typeof((mem[j]).begin()) it = (mem[j]).begin(); it != (mem[j]).end(); it++) { int nd = *it; vis[nd] = 1; st.push(nd); all++; for (int k = 0; k < int(adj[nd].size()); k++) { int to = adj[nd][k]; if (vis[to]) merge(to, nd); } } } dp[i] += all; all = 0; while (!st.empty()) { int nd = st.top(); st.pop(); ata[nd] = nd; sz[nd] = 1; vis[nd] = 0; } } for (int i = 1; i < N; i++) if (dp[i]) printf("%d %lld\n", i, dp[i]); return 0; }
#include <bits/stdc++.h> using namespace std; const int N = 2e5 + 15; const int inf = 0x3f3f3f3f; struct edge { int v, nxt; }; int sum[N], maxsum[N], val[N], head[N], tot; edge e[N << 1]; bool used[N]; inline void init() { memset(head, -1, sizeof(head)); } inline void addEdge(int u, int v) { e[tot] = edge{v, head[u]}; head[u] = tot++; } inline int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); } void getRoot(int u, int pre, int size, int& rt) { sum[u] = 1, maxsum[u] = 0; for (int i = head[u]; ~i; i = e[i].nxt) { int v = e[i].v; if (v == pre || used[v]) { continue; } getRoot(v, u, size, rt); sum[u] += sum[v]; maxsum[u] = max(maxsum[u], sum[v]); } maxsum[u] = max(maxsum[u], size - sum[u]); if (rt == -1 || maxsum[u] < maxsum[rt]) { rt = u; } } void getMaxDis(int u, int pre, int d, int k, int& ansd) { ansd = max(ansd, d); for (int i = head[u]; ~i; i = e[i].nxt) { int v = e[i].v, nk = gcd(k, val[v]); if (v == pre || used[v] || nk == 1) { continue; } getMaxDis(v, u, d + 1, nk, ansd); } } int dfs(int u) { int ret = 0; used[u] = true; vector<int> vec; for (int i = head[u]; ~i; i = e[i].nxt) { int v = e[i].v; if (used[v]) { continue; } int nk = gcd(val[u], val[v]); if (nk > 1) { int ansd = 1; getMaxDis(v, u, 1, nk, ansd); vec.push_back(ansd); } int rt = -1; getRoot(v, u, sum[v], rt); ret = max(ret, dfs(rt)); } sort(vec.begin(), vec.end(), greater<int>()); vec.emplace_back(0); vec.emplace_back(0); ret = max(ret, vec[0] + vec[1] + (val[u] > 1)); return ret; } int main() { int n; while (~scanf("%d", &n)) { init(); for (int i = 1; i <= n; i++) { scanf("%d", &val[i]); } for (int i = 1; i <= n - 1; i++) { int u, v; scanf("%d%d", &u, &v); addEdge(u, v); addEdge(v, u); } int rt = -1; getRoot(1, -1, n, rt); printf("%d\n", dfs(rt)); } }
#include <bits/stdc++.h> using namespace std; const int MAX = 200000; vector<int> divisors[MAX + 3]; void sieve() { for (int i = 1; i <= MAX; i++) { for (int j = i; j <= MAX; j += i) { divisors[j].push_back(i); } } } int gcd(int x, int y) { if (!y) return x; return gcd(y, x % y); } int a[MAX + 3]; vector<int> edg[MAX + 3]; int bigChild[MAX + 3]; int sbtr[MAX + 3]; void dfs1(int u, int p = 0) { sbtr[u] = 1; bigChild[u] = 0; for (int v : edg[u]) { if (v == p) continue; dfs1(v, u); sbtr[u] += sbtr[v]; if (sbtr[v] > sbtr[bigChild[u]]) bigChild[u] = v; } } long long F[MAX + 3]; long long G[MAX + 3]; long long fr[MAX + 3]; int timer; int tstate[MAX + 3]; void update(int u, int p, int sgn, int g) { g = gcd(g, a[u]); for (int d : divisors[g]) { if (tstate[d] != timer) { tstate[d] = timer; fr[d] = 0; } fr[d] += sgn; } for (int v : edg[u]) { if (v == p) continue; update(v, u, sgn, g); } } void add(int u, int p, int g) { g = gcd(g, a[u]); for (int d : divisors[g]) { G[d] += (tstate[d] == timer) * fr[d]; } for (int v : edg[u]) { if (v == p) continue; add(v, u, g); } } int tin[MAX + 3]; void dfs2(int u, int isBig = 1, int p = 0) { for (int v : edg[u]) { if (v == p || bigChild[u] == v) continue; dfs2(v, 0, u); } if (bigChild[u]) dfs2(bigChild[u], 1, u); timer++; tin[u] = timer; for (int d : divisors[a[u]]) { if (tstate[d] != timer - 1) fr[d] = 0; tstate[d] = timer; G[d] += fr[d] + 1; fr[d]++; } for (int v : edg[u]) { if (v == p || bigChild[u] == v) continue; add(v, u, a[u]); update(v, u, 1, a[u]); } if (!isBig) { update(u, p, -1, a[u]); } } int main() { std::ios_base::sync_with_stdio(false); cin.tie(0); sieve(); int n; cin >> n; for (int i = 1; i <= n; i++) cin >> a[i]; for (int i = 1; i < n; i++) { int x, y; cin >> x >> y; edg[x].push_back(y); edg[y].push_back(x); } dfs1(1); dfs2(1); for (int i = MAX; i > 0; i--) { F[i] = G[i]; for (int j = i + i; j <= MAX; j += i) F[i] -= F[j]; } for (int i = 1; i <= MAX; i++) { if (F[i]) cout << i << " " << F[i] << "\n"; } return 0; }
#include <bits/stdc++.h> using namespace std; namespace Fread { const long long MAXN = 1 << 20; char buf[MAXN], *S, *T; inline char getchar() { if (S == T) { T = (S = buf) + fread(buf, 1, MAXN, stdin); if (S == T) return EOF; } return *S++; } } // namespace Fread inline long long read() { long long x(0), neg(1); char ch = getchar(); while (!isdigit(ch)) { if (ch == '-') neg = -1; ch = getchar(); } while (isdigit(ch)) { x = (x << 1) + (x << 3) + (ch - '0'); ch = getchar(); } return x * neg; } const long long MAXN = 2e5; bool prime[MAXN + 5]; long long p[MAXN + 5], cnt; long long a[MAXN + 5]; vector<long long> pr[MAXN + 5]; vector<long long> g[MAXN + 5]; inline void PRIME() { memset(prime, 1, sizeof(prime)); prime[0] = prime[1] = 0; for (long long i = 2; i <= MAXN; ++i) { if (prime[i]) p[++cnt] = i; for (long long j = 1; j <= cnt && i * p[j] <= MAXN; ++j) { prime[i * p[j]] = 0; if (i % p[j] == 0) break; } } } long long ans; long long dp[MAXN + 5][25]; inline void dfs(long long u, long long fa) { for (long long i = 0; i < g[u].size(); ++i) { long long v = g[u][i]; if (v == fa) continue; dfs(v, u); for (long long j = 0; j < pr[u].size(); ++j) { for (long long k = 0; k < pr[v].size(); ++k) { long long pri1 = pr[u][j], pri2 = pr[v][k]; if (pri1 != pri2) continue; ans = max(ans, dp[u][j] + dp[v][k] + 1); dp[u][j] = max(dp[u][j], dp[v][k] + 1); } } } } signed main() { PRIME(); bool flag = true; long long n = read(); for (long long i = 1; i <= n; ++i) { a[i] = read(); if (a[i] != 1) flag = false; long long tmp = a[i], now = 1; for (long long j = 1; p[j] * p[j] <= tmp; ++j) { if (tmp == 0) break; if (tmp % p[j] == 0) { pr[i].push_back(p[j]); while (tmp % p[j] == 0) { tmp /= p[j]; } } } if (tmp != 1) pr[i].push_back(tmp); } if (flag) { puts("0"); return 0; } for (long long i = 1; i < n; ++i) { long long u(read()), v(read()); g[u].push_back(v), g[v].push_back(u); } dfs(1, 0); printf("%lld\n", ans + 1); return 0; }
#include <bits/stdc++.h> using namespace std; const int maxn = 200000 + 10; struct edge { int u, v; } E[maxn]; int n, q, m, a[maxn], fa[maxn]; bool vis[maxn]; long long siz[maxn], f[maxn]; int getfa(int x) { return fa[x] == x ? x : fa[x] = getfa(fa[x]); } vector<int> d[maxn], p[maxn], e[maxn]; int main() { ios::sync_with_stdio(false); cin.tie(0); cin >> n; for (int i = 1; i <= n; ++i) cin >> a[i], fa[i] = i, siz[i] = 1, m = max(a[i], m); for (int i = 1; i < n; ++i) { cin >> E[i].u >> E[i].v; e[E[i].u].push_back(E[i].v); e[E[i].v].push_back(E[i].u); } for (int i = 1; i <= m; ++i) for (int j = i; j <= m; j += i) d[j].push_back(i); for (int i = 1; i <= n; ++i) for (int j = 0; j < d[a[i]].size(); ++j) p[d[a[i]][j]].push_back(i); int u, v; for (int i = m; i; --i) { long long tmp = 0; for (int j = 0; j < p[i].size(); ++j) vis[p[i][j]] = 1; for (int j = 0; j < p[i].size(); ++j) { u = p[i][j]; for (int k = 0; k < e[u].size(); ++k) { v = e[u][k]; if (!vis[v]) continue; int fu = getfa(u), fv = getfa(v); if (fu == fv) continue; tmp += siz[fu] * siz[fv]; fa[fv] = fu; siz[fu] += siz[fv]; } } f[i] = tmp; for (int j = i + i; j <= m; j += i) f[i] -= f[j]; for (int j = 0; j < p[i].size(); ++j) { u = p[i][j]; fa[u] = u; siz[u] = 1; for (int k = 0; k < e[u].size(); ++k) { v = e[u][k]; if (!vis[v]) continue; fa[v] = v; siz[v] = 1; } } for (int j = 0; j < p[i].size(); ++j) vis[p[i][j]] = 0; } for (int i = 1; i <= n; ++i) ++f[a[i]]; for (int i = 1; i <= 200000; ++i) if (f[i]) cout << i << ' ' << f[i] << endl; return 0; }