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#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define N 100005
ll n, m, x, y, z, f[N], d[N], r[N], s;
bool ish(ll q)
{
return q >= 0;
}
void go(ll w)
{
ll q = w, e = f[q];
while (e != f[e])
{
d[q] += d[e];
f[q] = f[e];
e = f[e];
}
}
void merge()
{
ll q = f[x], w = f[y], t = d[x] - d[y] + z;
if (r[q] < r[w])
swap(q, w), t = -t;
f[w] = q;
d[w] = t;
r[q] += r[w];
}
int main()
{
scanf("%lld%lld", &n, &m);
for (int i = 1; i <= n; i++)
f[i] = i, r[i] = 1;
for (int i = 0; i < m; i++)
{
scanf("%lld%lld%lld", &x, &y, &z);
go(x); go(y);
/*for (int i = 1; i <= n; i++)
cout << i << " " << d[i] << endl;*/
if (f[x] == f[y])
{
if(d[y]-d[x]!=z)
{
cout << "No\n";
return 0;
}
}
else
merge();
}
cout << "Yes\n";
return 0;
} |
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
struct node{
int to;
int far;
};
vector<node> v[100000];
int x[100000];
bool done[100000];
bool dfs(int i,int now){
done[i]=1;
x[i]=now;
for(auto itr:v[i]){
if(!done[itr.to]){
if(!dfs(itr.to,now+itr.far))return false;
}else if(x[itr.to]!=x[i]+itr.far)return false;
}
return true;
};
int main(void){
int n,m;
bool a=true;
cin>>n>>m;
for(int i=0;i<m;i++){
int l,r,d;
cin>>l>>r>>d;
v[l-1].push_back({r-1,d});
v[r-1].push_back({l-1,-d});
}
for(int i=0;i<n;i++)if(!done[i])if(!dfs(i,0))a=0;
string ans=(a)?"Yes":"No";
cout<<ans<<endl;
}
|
#include<bits/stdc++.h>
using namespace std;
int father[100500];
int dis[100500];
int seek(int x) {
if(father[x]==x)return x;
int a1=father[x];
int a2=seek(father[x]);
father[x]=a2;
dis[x]=dis[x]+dis[a1];
return a2;
}
int fd(int x) {
if(father[x]==x)return 0;
return fd(father[x])+dis[x];
}
int main(void) {
int num,cas,L,R,D;
cin>>num>>cas;
for(int i=0; i<=num; i++) {
father[i]=i;
dis[i]=0;
}
while(cas--) {
cin>>L>>R>>D;
int fl=seek(L);
int fr=seek(R);
if(fl==fr) {
if(dis[L]+D!=dis[R]) {
cout<<"No"<<endl;
return 0;
}
} else {
father[fr]=fl;
dis[fr]=fd(L)-fd(R)+D;
}
}
cout<<"Yes"<<endl;
return 0;
} |
#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
const int N=1000005;
int n,m;
int fa[N],dis[N];
int finds(int x) {
if(x==fa[x]) return x;
int ret=fa[x];
fa[x]=finds(fa[x]);
dis[x]+=dis[ret];
return fa[x];
}
int main() {
scanf("%d%d",&n,&m);
for (int i=1;i<=n;++i) fa[i]=i;
for (int i=1;i<=m;++i) {
int x,y,d;
scanf("%d%d%d",&x,&y,&d);
int fx=finds(x),fy=finds(y);
if(fx==fy && (dis[x]-dis[y])!=d) {
puts("No");
return 0;
}
if(fx!=fy) {
fa[fx]=fy;
dis[fx]=-dis[x]+dis[y]+d;
}
}
puts("Yes");
return 0;
}
|
#include <bits/stdc++.h>
#define maxn 100000
using namespace std;
typedef long long LL;
int fa[maxn], off[maxn];
int find(int x) {
if (fa[x] == x) return x;
int temp = fa[x];
fa[x] = find(fa[x]);
off[x] += off[temp];
return fa[x];
}
int main() {
// freopen("in.txt", "r", stdin);
int n, m;
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; ++i) fa[i] = i;
for (int i = 0; i < m; ++i) {
int l, r, d;
scanf("%d%d%d", &l, &r, &d);
int fl = find(l), fr = find(r);
if (fl == fr) {
if (off[r] - off[l] == d) continue;
else { puts("No"); return 0; }
}
else {
fa[fr] = fl;
off[fr] = d - off[r] + off[l];
}
}
puts("Yes");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100010;
typedef long long ll;
const int mod = 1e9 + 7;
#define X first
#define Y second
vector<pair<int, int> > E[MAXN];
bool flag = true;
bool vis[MAXN];
int d[MAXN];
void dfs(int x)
{
for (auto e: E[x])
{
int y = e.X, z = e.Y;
if (!vis[y])
{
vis[y] = true;
d[y] = d[x] + z;
dfs(y);
}
else if (d[y] != d[x] + z) flag = false;
}
}
int main()
{
//freopen("input", "r", stdin);
int n, m, x, y, z;
scanf("%d %d", &n, &m);
for (int i = 1; i <= m; ++i)
{
scanf("%d %d %d", &x, &y, &z);
E[x].push_back(make_pair(y, z));
E[y].push_back(make_pair(x, -z));
}
for (int i = 1; i <= n; ++i)
if (!vis[i]) vis[i] = true, d[i] = 0, dfs(i);
puts(flag? "Yes":"No");
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int> > adjlist[100005];
int inc[100005];
bitset<100005> vis;
int dist[100005];
bool flag=true;
void dfs(int v, int d) {
if (dist[v]==-1) dist[v]=d;
else if (dist[v]!=d) flag=false;
//printf("%d %d\n", v, dist[v]);
vis[v]=true;
for (auto it:adjlist[v]) {
if (!vis[it.first]) dfs(it.first, d+it.second);
if (d+it.second!=dist[it.first]) flag=false;
}
}
int main() {
memset(dist,-1,sizeof(dist));
int n, m;
scanf("%d%d", &n, &m);
for (int i=0; i<m; i++) {
int l,r,d;
scanf("%d%d%d", &l, &r, &d);
l--; r--;
adjlist[l].push_back({r,d});
inc[r]++;
}
for (int i=0; i<n; i++) {
if (vis[i]||inc[i]) continue;
dfs(i,0);
}
for (int i=0; i<n; i++) flag &= vis[i];
printf("%s\n", flag?"Yes":"No");
}
|
#include <iostream>
#include <stdio.h>
#include <string.h>
#define MAX_N 100005
#define int long long
using namespace std;
int n,m;
int par[MAX_N];
int dis[MAX_N];
int find(int x)
{
if(par[x]==x) return x;
int p=par[x];
par[x]=find(par[x]),dis[x]+=dis[p];
return par[x];
}
bool unite(int x,int y,int z)
{
int px=find(x),py=find(y);
if(px==py) return dis[x]-dis[y]==z;
dis[px]=-dis[x]+z+dis[y],par[px]=py;
return true;
}
signed main()
{
scanf("%lld%lld",&n,&m);
for(int i=1;i<=n;i++) par[i]=i;
int l,r,d;
for(int i=1;i<=m;i++)
{
scanf("%lld%lld%lld",&l,&r,&d);
if(!unite(l,r,d))
{
printf("No\n");
return 0;
}
}
printf("Yes\n");
}
|
#include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
#define f first
#define pb push_back
#define s second
#define mp make_pair
int d[100100];
vector<pi> aList[100100];
int N,M,a,b,c;
int INF = 1e9;
void dfs(int x){
for (auto i : aList[x]){
int nxt = d[x] + i.s;
if (d[i.f] == -INF){
d[i.f] = nxt;
dfs(i.f);
}else{
if (nxt != d[i.f]){
cout<<"No";
exit(0);
}
}
}
}
int main(){
cin >> N >> M;
for (int i=0;i<M;++i){
cin>>a>>b>>c;
aList[a].pb(mp(b,c));
aList[b].pb(mp(a,-c));
}
for (int i=1;i<=N;++i)d[i] = -INF;
for (int i=1;i<=N;++i){
if (d[i] != -INF)continue;
d[i] = d[i-1];
dfs(i);
}
cout<<"Yes";
} |
#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+10;
int n,m,fa[maxn],pos[maxn];
int findfa(int x){
if(fa[x]==x)return x;
int f=findfa(fa[x]);
pos[x]=pos[x]+pos[fa[x]];
fa[x]=f;
return f;
}
int main(){
cin>>n>>m;
for(int i=1;i<=n;++i)
fa[i]=i;
for(int i=1,l,r,d;i<=m;++i){
cin>>l>>r>>d;
if(findfa(l)==findfa(r)){
if(pos[l]+d!=pos[r]){
puts("No");
return 0;
}
}
else{
int x=findfa(l),y=findfa(r);
fa[y]=x;
pos[y]=pos[l]+d-pos[r];
}
}
puts("Yes");
return 0;
} |
#include<cstdio>
using namespace std;
const int N = 1e5;
int fa[N+2];
long long fv[N+2];
int n,q;
int find_fa(int u)
{
int i = u; long long t = 0ll;
while(u!=fa[u]) {t += fv[u]; u = fa[u];}
long long k = fv[i];
fv[i] = t;
while(i!=u)
{
t -= k;
int j = fa[i];
fa[i] = u;
i = j;
k = fv[i];
fv[i] = t;
}
return u;
}
int main()
{
scanf("%d%d",&n,&q); bool ans = true;
for(int i=1; i<=n; i++) {fa[i] = i; fv[i] = 0ll;}
for(int i=1; i<=q; i++)
{
int x,y; long long z; scanf("%d%d%lld",&x,&y,&z);
int p = find_fa(x),q = find_fa(y);
if(p!=q)
{
fa[q] = p; fv[q] = fv[x]+z-fv[y];
}
else
{
if(z!=fv[y]-fv[x]) {ans = false; break;}
}
}
if(ans==true) printf("Yes\n");
else printf("No\n");
return 0;
} |
#include <iostream>
#include <vector>
using namespace std;
const int MAXN = 1e5 + 10, MAXM = 2e5 + 10;
vector<pair<int, int> > vc[MAXN];
vector<pair<int, pair<int, int> > > e;
long long d[MAXN], n, m;
bool se[MAXN];
void dfs(int v, long long dis) {
d[v] = dis;
se[v] = 1;
for (int i = 0; i < vc[v].size(); i++)
if (!se[vc[v][i].first])
dfs(vc[v][i].first, dis + vc[v][i].second);
}
int main() {
cin >> n >> m;
for (int i = 0; i < m; i++) {
int li, ri, di;
cin >> li >> ri >> di;
vc[li].push_back({ri, di});
vc[ri].push_back({li, -di});
e.push_back({di, {li, ri}});
}
for (int i = 1; i <= n; i++)
if (!se[i])
dfs(i, 0);
for (int i = 0; i < m; i++)
if (d[e[i].second.second] - d[e[i].second.first] != e[i].first)
return cout << "No", 0;
cout << "Yes";
} |
#include<bits/stdc++.h>
#define pb push_back
#define ins insert
#define F first
#define S second
#define var auto
using namespace std;
typedef long long ll;
const int Max = 1e5 + 10;
const int Mod = 1e9 + 7;
bool seen[Max];
vector<pair<int,int> > N[Max];
bool ok = true;
int dist[Max];
void DFS(int v)
{
seen[v] = true;
for(auto u : N[v])
{
if(seen[u.F])
ok &= dist[u.F] == dist[v] + u.S;
else
{
dist[u.F] = dist[v] + u.S;
DFS(u.F);
}
}
}
int main()
{
int n , m;cin >> n >> m;
for(int i = 0; i < m ; i++)
{
int l , r , d;cin >> l >> r >> d;
N[l].pb({r , d});
N[r].pb({l , -d});
}
for(int i = 1; i <= n ; i++)
{
if(!seen[i])
{
dist[i] = 0;
DFS(i);
}
}
if(ok)
cout << "Yes\n";
else
cout << "No\n";
}
|
#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef pair<int , int> pii;
const int N = 100100;
vector <pii> adj[N];
bool mark[N];
int dist[N];
void DFS(int v){
mark[v] = 1;
for(auto u : adj[v]){
int t = dist[v] + u.S;
if(!mark[u.F]){
dist[u.F] = t;
DFS(u.F);
}
else if(dist[u.F] != t){
cout << "No" << endl;
exit(0);
}
}
return;
}
int main(){
ios_base::sync_with_stdio(0) , cin.tie(0) , cout.tie(0);
int n , m , l , r , d;
cin >> n >> m;
for(int i = 0 ; i < m ; i++){
cin >> l >> r >> d;
adj[--l].pb({--r , d});
adj[r].pb({l , -d});
}
for(int i = 0 ; i < n ; i++)
if(!mark[i])
DFS(i);
cout << "Yes" << endl;
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
#define MAX_N 100001
vector<pair<int, int64_t> > adj[MAX_N];
int64_t dis[MAX_N];
void dfs(int v, int64_t d)
{
if (dis[v]) {
if (dis[v] != d) {
printf("No\n");
exit(0);
}
return;
}
dis[v] = d;
for (int i = 0; i < adj[v].size(); i++) {
int u = adj[v][i].first;
int64_t w = adj[v][i].second;
dfs(u, d + w);
}
}
int main(void)
{
int n, m;
scanf("%d%d", &n, &m);
for (int i = 0; i < m; i++) {
int l, r, d;
scanf("%d%d%d", &l, &r, &d);
adj[l].push_back(make_pair(r, d));
adj[r].push_back(make_pair(l, -d));
}
for (int i = 1; i <= n; i++)
if (!dis[i]) dfs(i, 0xffff);
printf("Yes\n");
return 0;
}
|
#include<bits/stdc++.h>
using namespace std;
int fr[100005],nex[400005],vi[400005],wi[400005],tot=0;
void add(int x,int y,int z){
nex[++tot]=fr[x];vi[tot]=y;wi[tot]=z;fr[x]=tot;
}
int n,m,vs[100005],d[100005];
void dfs(int x,int fa){
vs[x]=1;
for(int i=fr[x];i;i=nex[i])if(fa!=vi[i]){
if(d[vi[i]]!=0x7f7f7f7f){
if(wi[i]!=d[vi[i]]-d[x]){
puts("No");exit(0);
}
}else{
d[vi[i]]=d[x]+wi[i];
dfs(vi[i],x);
}
}
}
int main(){
scanf("%d%d",&n,&m);
for(int i=1,x,y,z;i<=m;++i){
scanf("%d%d%d",&x,&y,&z);
add(x,y,z);
add(y,x,-z);
}
memset(d,0x7f,sizeof d);
for(int i=1;i<=n;++i)if(!vs[i])dfs(i,i);
puts("Yes");
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int n,m,fa[N],cnt[N];
void find(int x)
{
if (fa[x]==x) return;
find(fa[x]);
cnt[x]+=cnt[fa[x]],fa[x]=fa[fa[x]];
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1; i<=n; ++i)
fa[i]=i;
for(int i=1,x,y,z; i<=m; ++i)
{
scanf("%d%d%d",&x,&y,&z);
find(x),find(y);
if(fa[x]==fa[y])
{
if(cnt[x]+z!=cnt[y])
{
puts("No");
return 0;
}
}
else
{
cnt[fa[y]]=cnt[x]+z-cnt[y];
fa[fa[y]]=fa[x];
}
}
puts("Yes");
return 0;
}
|
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const long long MAXN=100005;
long long fa[MAXN],jl[MAXN];
long long n,m;
long long find(long long x)
{
if(fa[x]==x)
return x;
long long f=find(fa[x]);
jl[x]=jl[fa[x]]+jl[x];
fa[x]=f;
return f;
}
int main()
{
scanf("%lld %lld",&n,&m);
for(long long i=1;i<=n;i++)
fa[i]=i,jl[i]=0;
for(long long i=1;i<=m;i++)
{
long long l,r,d;
scanf("%lld %lld %lld",&l,&r,&d);
long long a=find(l),b=find(r);
if(a==b)
{
if(jl[l]-jl[r]!=d)
{
printf("No\n");
return 0;
}
}
else
{
fa[b]=a;
jl[b]=-d+jl[l]-jl[r];
}
}
printf("Yes\n");
} |
#include<bits/stdc++.h>
const long long maxn=1e5+100;
using namespace std;
long long n,m,k,t,f[maxn],x,y,d[maxn];bool le;
int getf(int u)
{
int k;
if(f[u]==u)
return u;
k=f[u];
f[u]=getf(f[u]);
d[u]=d[u]+d[k];
return f[u];
}
void jia(int x,int y,int k)
{
int i,j;
i=getf(x);
j=getf(y);
f[j]=i;
d[j]=d[x]-d[y]-k;
}
int main()
{
scanf("%lld%lld",&n,&m);
for(int i=1;i<=n;++i)
f[i]=i;
for(int i=1;i<=m;++i)
{
scanf("%lld%lld%lld",&x,&y,&k);
if(getf(x)!=getf(y))
jia(y,x,k);
else
if(d[y]-d[x]!=k)
{
le=1;
}
}
if(le)
printf("No\n");
else
printf("Yes\n");
return 0;
}
|
#include <bits/stdc++.h>
#define ll long long int
#define mod 1000000007
#define pii pair<int, int>
#define fr(n) for (int i = 0; i < n; i++)
#define fr1(n) for (int i = 1; i <= n; i++)
using namespace std;
vector<pii> g[100005];
int d[100005];
bool b[100005];
void dfs(int x) {
for (pii i : g[x]) {
if (!b[i.first]) {
b[i.first] = 1;
d[i.first] = d[x] + i.second;
dfs(i.first);
} else {
if (d[i.first] != d[x] + i.second) {
cout << "No";
exit(0);
}
}
}
}
int main() {
ios::sync_with_stdio(false);
int n, m, u, v, w;
cin >> n >> m;
fr(m) cin >> u >> v >> w, g[u].push_back({v, w}), g[v].push_back({u, -w});
fr1(n) if (!b[i]) b[i] = 1, dfs(i);
cout << "Yes";
}
|
#include <bits/stdc++.h>
using namespace std;
const int MAXn = 1e5 + 10;
typedef pair<int, int> pii;
vector<pii> g[MAXn];
long long n, m, dis[MAXn];
bool flag[MAXn];
void dfs(int v, long long dist) {
flag[v] = true;
dis[v] = dist;
for (pii u : g[v]) {
if (flag[u.first])
continue;
dfs(u.first, dist + u.second);
}
}
int main() {
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v, d;
cin >> u >> v >> d;
g[u].push_back(pii(v, d));
g[v].push_back(pii(u, -d));
}
for (int i = 1; i <= n; i++) {
if (!flag[i]) {
dfs(i, 0);
}
}
for (int i = 1; i <= n; i++)
for (pii u : g[i])
if (dis[i] + u.second != dis[u.first])
return cout << "No",0;
cout << "Yes";
}
|
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
int x[100009];
bool vs[100009];
vector<pii> adj[100009];
void go(int now) {
vs[now] = 1;
for(auto& it: adj[now]) {
if(!vs[it.first]) {
x[it.first] = x[now] + it.second;
go(it.first);
}
}
}
int main() {
int N, M; scanf("%d%d",&N,&M);
for(int i=0; i<M; i++) {
int L, R, D; scanf("%d%d%d",&L,&R,&D);
adj[L].push_back({R, D});
adj[R].push_back({L, -D});
}
for(int i=1; i<=N; i++) if(!vs[i]) go(i);
for(int i=1; i<=N; i++) {
for(auto& it: adj[i]) {
if(x[i] + it.second != x[it.first]) return !printf("No");
}
}
puts("Yes");
return 0;
}
|
#include<cstdio>
using namespace std;
int n, m, pre[100005], dist[100005];
inline int find(int x){
if(pre[x]^x) {
int nf = pre[x]; pre[x] = find(pre[x]); dist[x] += dist[nf];
}
return pre[x];
}
int main(){
bool flag=true;
scanf("%d%d", &n, &m);
for(register int i=1; i<=n; ++i)pre[i]=i;
for(register int i=1; i<=m; ++i){
int l, r, delta;
scanf("%d%d%d", &l, &r, &delta);
int ll = find(l), rr = find(r);
if(ll==rr&&dist[l]-dist[r]!=delta)flag=false;
if(ll^rr){
pre[ll] = rr;
dist[ll] = delta + dist[r] - dist[l];
}
}
if(flag)printf("Yes\n");
else printf("No\n");
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
int fa[100005],k[100005];
int f(int u)
{
if(u==fa[u])
return u;
else
{
int t=f(fa[u]);
k[u]+=k[fa[u]];
return fa[u]=t;
}
}
int main()
{
int i,l,r,d,p,q,n,m;
cin>>n>>m;
for(i=1;i<=n;i++)
{
fa[i]=i;
k[i]=0;
}
for(i=1;i<=m;i++)
{
cin>>l>>r>>d;
if(f(l)==f(r))
{
if(k[r]-k[l]!=d)
{
puts("No");
return 0;
}
}
else
{
p=f(r),q=f(l);
fa[p]=q;
k[p]=k[l]-k[r]+d;
}
}
puts("Yes");
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
int n,m,fa[202000],d[202000];
int GF(int x){
if (fa[fa[x]]==fa[x]) return fa[x];
int orgfa=fa[x];
fa[x]=GF(fa[x]);
d[x]+=d[orgfa];
return fa[x];
}
int dis(int x){
return fa[x]==x? 0: d[x]+dis(fa[x]);
}
void onion(int x,int y,int v){
int fx=GF(x), dx=dis(x), fy=GF(y), dy=dis(y), las;
las=-dx+dy+v;
if (fx==fy){
if (las){
puts("No");
exit(0);
}
}else{
fa[fx]=fy;
d[fx]=las;
}
}
int main(){
cin>>n>>m;
for (int i=1;i<=n;++i)
fa[i]=i, d[i]=0;
int l,r,x;
for (;m--;){
scanf("%d%d%d",&l,&r,&x);
onion(r,l,x);
}
puts("Yes");
}
|
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define st first
#define nd second
typedef pair < int , int > pp;
const int mod = 1e9 + 7;
const int N = 2e5 + 5;
vector < pp > V[N];
int T[N],H[N],n,m,i,x,y,z;
void f(int x){
H[x] = 1;
for(int y, i=0; i<V[x].size(); i++){
if(!H[ y = V[x][i].st ]){
T[y] = T[x] + V[x][i].nd;
f(y);
}
else if(T[y] != T[x] + V[x][i].nd){
puts("No"); exit(0);
}
}
}
signed main(){
scanf("%d%d",&n,&m);
for(; m-- ;){
scanf("%d%d%d",&x,&y,&z);
V[x].pb(mp(y,z));
V[y].pb(mp(x,-z));
}
for(i=1;i<=n;i++){
if(H[i]) continue;
f(i);
}
puts("Yes");
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
int main() {
int n, m;
cin >> n >> m;
vector<vector<pair<int, int>>> v(n, vector<pair<int, int>>());
for (int i = 0; i < m; i++) {
int l, r, d;
cin >> l >> r >> d;
l--;
r--;
v[l].push_back(make_pair(r, d));
v[r].push_back(make_pair(l, -d));
}
bool f = true;
vector<int> x(n, INT_MAX);
for (int i = 0; i < n && f; i++) {
if (x[i] == INT_MAX) {
x[i] = 0;
queue<int> q;
q.push(i);
while (!q.empty() && f) {
int j = q.front();
q.pop();
for (auto p : v[j]) {
if (x[p.first] == INT_MAX) {
x[p.first] = x[j] + p.second;
q.push(p.first);
} else {
if (x[p.first] != x[j] + p.second) {
f = false;
break;
}
}
}
}
}
}
cout << (f ? "Yes" : "No") << endl;
return 0;
}
|
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
const int N=1e5+5;
const int INF=0x3f3f3f;
int par[N];
int v[N];
int Find(int x){
int temp=par[x];
if(par[x]!=x) par[x]=Find(par[x]),v[x]+=v[temp];
return par[x];
}
int main(void){
int n,m;
cin >>n >>m;
for(int i=1;i<=n;i++) par[i]=i;
bool flag=true;
for(int i=1;i<=m;i++){
int l,r,d;
scanf("%d%d%d",&l,&r,&d);
int rootl=Find(l);
int rootr=Find(r);
if(rootr==rootl){
if(v[r]-v[l]!=-d) flag=false;
}
else{
par[rootl]=rootr;
v[rootl]=d+v[r]-v[l];
}
}
if(flag) cout <<"Yes"<<endl;
else cout<<"No"<<endl;
}
|
#include <bits/stdc++.h>
#define MAXN 200100
#define pii pair<int, int>
#define pb push_back
typedef long long ll;
using namespace std;
int n, m, l[MAXN], r[MAXN], d[MAXN], p[MAXN];
vector<pii> g[MAXN];
bool vis[MAXN];
void dfs(int x, int pos){
if(vis[x]) return;
vis[x] = true;
p[x] = pos;
for(auto i : g[x]){
dfs(i.first, i.second + pos);
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m;
for(int i = 0; i < m; i++){
cin >> l[i] >> r[i] >> d[i];
l[i]--;
r[i]--;
g[l[i]].pb({r[i], d[i]});
g[r[i]].pb({l[i], -d[i]});
}
for(int i = 0; i < n; i++)
dfs(i, 0);
for(int i = 0; i < m; i++){
if(p[r[i]] - p[l[i]] != d[i]){
cout << "No";
return 0;
}
}
cout << "Yes";
} |
#include <bits/stdc++.h>
#define maxn 100000
using namespace std;
typedef long long LL;
int fa[maxn], off[maxn];
int find(int x) {
if (fa[x] == x) return x;
int temp = fa[x];
fa[x] = find(fa[x]);
off[x] += off[temp];
return fa[x];
}
int main() {
int n, m;
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; ++i) fa[i] = i;
for (int i = 0; i < m; ++i) {
int l, r, d;
scanf("%d%d%d", &l, &r, &d);
int fl = find(l), fr = find(r);
if (fl == fr) {
if (off[r] - off[l] == d) continue;
else { puts("No"); return 0; }
}
else {
fa[fr] = fl;
off[fr] = d - off[r] + off[l];
}
}
puts("Yes");
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define f(i, x, n) for(int i = x; i < (int)(n); ++i)
int const N = 100000;
map<int, int> mp[N + 1];
int pa[N + 1];
int main(){
int n, m;
scanf("%d%d", &n, &m);
f(i, 1, n + 1)pa[i] = i;
f(i, 1, n + 1)mp[i][i] = 0;
while (m--){
int l, r, d;
scanf("%d%d%d", &l, &r, &d);
if (pa[l] == pa[r]) { if (mp[pa[l]][r] - mp[pa[l]][l] != d) { printf("No\n"); return 0; } }
else {
int pl = pa[l], pr = pa[r];
if (mp[pl].size() > mp[pr].size())swap(pl, pr), swap(l, r), d = -d;
int z = mp[pr][r] - d - mp[pl][l];
for (map<int, int>::iterator it = mp[pl].begin(); it != mp[pl].end(); mp[pl].erase(it++)){
pa[it->first] = pr;
mp[pr][it->first] = it->second + z;
}
}
}
printf("Yes\n");
} |
#include <bits/stdc++.h>
using namespace std;
int N, M;
vector<vector<pair<int,int>>> A;
vector<bool> visited;
vector<int> pos;
bool g(int p, int q) {
if (visited[p]) {
return pos[p] == q;
} else {
visited[p] = true;
pos[p] = q;
for (auto x : A[p]) {
if (!g(x.first, q + x.second)) return false;
}
return true;
}
}
bool f() {
visited.resize(N);
pos.resize(N);
for (int i = 0; i < N; ++ i) if (!visited[i]) {
if (!g(i, 0)) return false;
}
return true;
}
int main() {
cin >> N >> M;
A.resize(N);
for (int i = 0; i < M; ++ i) {
int Li, Ri, Di;
cin >> Li >> Ri >> Di;
-- Li; -- Ri;
A[Li].push_back({Ri, Di});
A[Ri].push_back({Li, -Di});
}
cout << (f() ? "Yes" : "No") << endl;
}
|
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int fa[N];
int dis[N];
int n,m,x,y,d;
void init()
{
for(int i=1;i<=n;i++)
fa[i]=i,dis[i]=0;
}
int find(int x)
{
if(fa[x]==x)return x;
int k=fa[x];
fa[x]=find(fa[x]);
dis[x]+=dis[k];
return fa[x];
}
void merge(int x,int y)
{
int xx=find(x),yy=find(y);
fa[yy]=xx;
dis[yy]=dis[x]+d-dis[y];
}
int main()
{
cin>>n>>m;
init();
while(m--)
{
cin>>x>>y>>d;
if(find(x)!=find(y))
{
merge(x,y);
}
else{
if(dis[y]-dis[x]!=d)
{
puts("No");
return 0;
}
}
}
cout<<"Yes"<<endl;
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
int n,m,fa[N],dis[N];
int find(int x){
if (x==fa[x]) return x;
int y=fa[x];
fa[x]=find(fa[x]);
dis[x]+=dis[y];
return fa[x];
}
int main()
{
scanf("%d%d",&n,&m);
for (int i=1;i<=n;i++) fa[i]=i;
for (int i=1;i<=m;i++){
int l,r,d;
scanf("%d%d%d",&l,&r,&d);
int x=find(l),y=find(r);
if (x==y&&dis[l]+d!=dis[r]) return puts("No"),0;
if (x==y) continue;
fa[x]=y;
dis[x]=dis[r]-d-dis[l];
}
puts("Yes");
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+5;
int type[maxn],dis[maxn];
int find(int a)
{
if(type[a]==a) return a;
else
{
int pre=type[a];
type[a]=find(type[a]);
dis[a]+=dis[pre];
return type[a];
}
}
void fl()
{
freopen(".in","r",stdin);
freopen(".out","w",stdout);
}
int main()
{
// fl();
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n,m;
cin>>n>>m;
for(int i=1;i<=n;i++)
type[i]=i;
bool check=true;
for(int i=1;i<=m;i++)
{
int l,r,d;
cin>>l>>r>>d;
if(!check) continue;
int l_=find(l),r_=find(r);
if(l_==r_)
{
if(dis[r]-dis[l]!=d) check=false;
}
else
{
type[r_]=l_;
dis[r_]=dis[l]+d-dis[r];
}
}
if(check) puts("Yes");
else puts("No");
return 0;
}
|
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int n,m,x,y,z,fa[N],sum[N];
int Read()
{
int x=0,f=1;
char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch)){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
return f*x;
}
int Get(int x)
{
if(fa[x]==x) return x;
int f=fa[x];
fa[x]=Get(f);
sum[x]+=sum[f];
return fa[x];
}
void merge(int a,int b,int c)
{
int f1=Get(a),f2=Get(b);
fa[f1]=f2;
sum[f1]=-sum[a]+sum[b]+c;
}
int main()
{
// freopen("line.in","r",stdin);
//freopen("line.out","w",stdout);
n=Read(),m=Read();
for(int i=1;i<=n;i++) fa[i]=i;
for(int i=1;i<=m;i++)
{
x=Read(),y=Read(),z=Read();
int f1=Get(x),f2=Get(y);
if(f1==f2)
{
if(sum[x]-sum[y]!=z)
{
cout<<"No";
return 0;
}
}
else
merge(x,y,z);
}
cout<<"Yes";
return 0;
} |
#include <iostream>
using namespace std;
const int maxn=1000005;
int fa[maxn];
int dis[maxn];
int Find(int x)
{
if(fa[x]==x)
return x;
int r=Find(fa[x]);
dis[x]=dis[fa[x]]+dis[x];
return fa[x]=r;
}
int Union(int x,int y,int z)
{
int fx=Find(x);
int fy=Find(y);
if (fx==fy)
return z==dis[y]-dis[x];
fa[fy]=fx;
dis[fy]=dis[x]+z-dis[y];
return 1;
}
int main()
{
int n,m;
int flag= 1;
cin>>n>>m;
for (int i=1;i<=n;i++)
fa[i]=i;
for (int i=1;i<=m;i++)
{
int l,r,d;
cin>>l>>r>>d;
if (flag)
flag=Union(l,r,d);
}
if (flag)
cout<<"Yes"<<endl;
else
cout<<"No"<<endl;
return 0;
}
|
#include<iostream>
#define int long long
using namespace std;
int n,p[200000],w[200000],m;
int find(int x)
{
if(p[x]==x)return x;
int F=p[x];
p[x]=find(p[x]);
w[x]+=w[F];
return p[x];
}
signed main()
{
cin>>n>>m;
for(int i=1;i<=n;i++)p[i]=i;
while(m--)
{
int l,r,d;
cin>>l>>r>>d;
int x=find(l),y=find(r);
if(x==y&&w[r]-w[l]!=d){cout<<"No"<<endl;return 0;}
else p[y]=x,w[y]=w[l]+d-w[r];
}
cout<<"Yes"<<endl;
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
typedef long long lint;
typedef pair<int, int> pi;
const int MAXN = 100005;
int n, m;
vector<pi> gph[MAXN];
bool vis[MAXN], bad;
int col[MAXN];
void dfs(int x, int c){
if(vis[x]){
if(col[x] != c) bad = 1;
return;
}
vis[x] = 1;
col[x] = c;
for(auto &i : gph[x]) dfs(i.second, c + i.first);
}
int main(){
scanf("%d %d",&n,&m);
for(int i=0; i<m; i++){
int s, e, x; scanf("%d %d %d",&s,&e,&x);
gph[s].emplace_back(x, e);
gph[e].emplace_back(-x, s);
}
for(int i=1; i<=n; i++){
if(!vis[i]){
dfs(i, 0);
}
}
puts(!bad ? "Yes" : "No");
}
|
#include <bits/stdc++.h>
using namespace std;
const int N=400005;
int cnt,h[N],to[N],las[N],c[N];
int vis[N],val[N],n,m,u,v,w;
void dfs(int x)
{
vis[x]=1;
int i;
for(i=h[x];i;i=las[i])
if(!vis[to[i]])
{
val[to[i]]=val[x]+c[i];
dfs(to[i]);
}
else if(val[to[i]]!=val[x]+c[i])
{
printf("No");
exit(0);
}
}
int main()
{
scanf("%d%d",&n,&m);
int i;
for(i=1;i<=m;i++)
{
scanf("%d%d%d",&u,&v,&w);
las[++cnt]=h[u],h[u]=cnt,to[cnt]=v,c[cnt]=w;
las[++cnt]=h[v],h[v]=cnt,to[cnt]=u,c[cnt]=-w;
}
for(i=1;i<=n;i++)
if(!vis[i])
dfs(i);
printf("Yes");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
const int maxn = 100010;
int pa[maxn], d[maxn];
int n, m;
int findset(int x)
{
if(pa[x] == x)return x;
int t = findset(pa[x]);
d[x] += d[pa[x]];
pa[x] = t;
return pa[x];
}
int main()
{
memset(d, 0, sizeof(d));
scanf("%d%d", &n, &m);
for(int i = 0; i <= n; i++)
pa[i] = i;
for(int i = 1; i <= m; i++) {
int x, y, w;
scanf("%d%d%d", &x, &y, &w);
int p = findset(x), q = findset(y);
if(p != q) {
pa[p] = q;
d[p] = d[y] - (d[x] + w);
} else if(d[y] - d[x] != w) {
printf("No\n");
return 0;
}
}
printf("Yes\n");
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int,int>;
const int mx = 1e5 + 5;
int vis[mx], val[mx];
int n, m;
vector<pii> G[mx];
bool dfs(int x){
vis[x] = 1;
for(pii u : G[x]){
if(vis[u.first]){
if(val[u.first] != val[x] + u.second) return false;
else continue;
}
val[u.first] = val[x] + u.second;
if(!dfs(u.first)) return false;
}
return true;
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin >> n >> m;
for(int i = 0, a, b, w; i < m; i++){
cin >> a >> b >> w;
G[a].emplace_back(b,w);
G[b].emplace_back(a,-w);
}
for(int i = 1; i <= n; i++){
if(!vis[i] && !dfs(i)){
cout << "No\n";
return 0;
}
}
cout << "Yes\n";
} |
#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<algorithm>
using namespace std;
int n,m;
int pa[233333],dis[233333];
pair<int,int> find(int x)
{
if(pa[x]==0)return make_pair(x,0);
else
{
pair<int,int> tmp=find(pa[x]);
dis[x]+=tmp.second;pa[x]=tmp.first;
return make_pair(pa[x],dis[x]);
}
}
int main()
{
scanf("%d%d",&n,&m);
int l,r,d;
while(m--)
{
scanf("%d%d%d",&l,&r,&d);
pair<int,int> pl=find(l),pr=find(r);
if(pl.first==pr.first&&pl.second+d!=pr.second)
{
return printf("No\n"),0;
}
else if(pl.first!=pr.first)
{
pa[pr.first]=pl.first;
dis[pr.first]=d-pr.second+pl.second;
}
}
printf("Yes\n");
return 0;
} |
#include<cstdio>
const int maxn=100000;
int n,m,fa[maxn+10],dfa[maxn+10];
int getfa(int x){
/* int u=x,d=0;
for(;fa[u]!=u;u=fa[u]) d+=dfa[u];
for(int i=x,p;fa[i]!=i;i=p){
p=fa[i]; fa[i]=u; d-=dfa[i]; dfa[i]+=d;
}*/
if(fa[x]==x) return x;
int f=getfa(fa[x]); dfa[x]+=dfa[fa[x]]; return fa[x]=f;
}
int main(){
scanf("%d%d",&n,&m);
for(int i=1;i<=n;++i) fa[i]=i;
for(int i=1;i<=m;++i){
int l,r,d; scanf("%d%d%d",&l,&r,&d);
int ll=getfa(l),rr=getfa(r);
if(ll!=rr){
fa[ll]=rr; dfa[ll]=dfa[r]-dfa[l]-d;
}else if(dfa[r]-dfa[l]-d){
printf("No"); return 0;
}
}
printf("Yes");
} |
#include <cstdio>
int d[120000],f[120000],h[120000];
int i,m,n,x,y,dx,dy,fx,fy,z;
inline int getfather(int x)
{
if (f[x]==x)
return x;
else
return getfather(f[x]);
}
inline int getdis(int x)
{
if (f[x]==x)
return 0;
else
return d[x]+getdis(f[x]);
}
int main()
{
scanf("%d%d",&n,&m);
for (i=1;i<=n;i++)
f[i]=i,h[i]=1;
for (i=1;i<=m;i++)
{
scanf("%d%d%d",&x,&y,&z);
fx=getfather(x);
fy=getfather(y);
if (fx!=fy)
if (h[fx]<h[fy])
d[fx]=z-getdis(x)+getdis(y),f[fx]=fy,h[fy]=h[fy]+h[fx];
else
d[fy]=-z-getdis(y)+getdis(x),f[fy]=fx,h[fx]=h[fx]+h[fy];
else
{
dx=getdis(x);
dy=getdis(y);
if (dx!=dy+z)
return puts("No"),0;
}
}
return puts("Yes"),0;
} |
#include<iostream>
#include<cstdio>
#include<vector>
using namespace std;
int p[5],v[100005],o[100005],f=1;
vector<int>b[100005];
void dfs(int a,int d){
int i;
//cout<<a<<' '<<d<<endl;
if(o[a]!=0){
if(v[a]!=d)f=0;
return;
}
v[a]=d;
o[a]=1;
for(i=0;i<b[a].size();i+=2){
dfs(b[a][i],d+b[a][i+1]);
}
return;
}
int main(){
int n,m,i;
cin>>n>>m;
for(i=1;i<=m;i++){
cin>>p[1]>>p[2]>>p[3];
b[p[1]].push_back(p[2]);
b[p[1]].push_back(p[3]);
b[p[2]].push_back(p[1]);
b[p[2]].push_back(0-p[3]);
}
for(i=1;i<=n;i++){
if(o[i]==0)dfs(i,0);
}
if(f==1)
cout<<"Yes"<<endl;
else
cout<<"No"<<endl;
return 0;
} |
#include <iostream>
#include <vector>
using namespace std;
int main() {
int N;
cin >> N;
int S = 0;
int seq = 0;
int p;
for(int i = 1; i <= N; i++) {
cin >> p;
if(i != p) {
S += seq / 2 + seq % 2;
seq = 0;
}
if(i == p) seq++;
}
S += seq / 2 + seq % 2;
cout << S << endl;
return 0;
} |
#include<cstdio>
int a[100000+5],n;
void swp(int x,int y){
int t=a[x];
a[x]=a[y];
a[y]=t;
}
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&a[i]);
}
int ans=0;
for(int i=1;i<=n;i++){
if(a[i]==i){
swp(i,i+1);
ans++;
}
}
printf("%d",ans);
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int a[100010];
int main(){
int n, ans = 0;
scanf("%d", &n);
for(int i = 1;i <= n;i++)scanf("%d", &a[i]);
for(int i = 1;i <= n;i++){
if(a[i] == i){
ans++;
if(a[i+1] == i+1)i++;
}
}
printf("%d\n", ans);
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
int main() {
int N;
cin >> N;
int total = 0;
int continuous = false;
for(int i=0;i<N;i++) {
int a;
cin >> a;
if(!continuous && a == i+1) {
continuous = true;
total++;
} else {
continuous = false;
}
}
cout << total << endl;
} |
#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
int n,i,s;
cin >> n;
vector<int> p(n);
for(i=0;i<n;i++){
cin >> p.at(i);
}
s=0;
for(i=0;i<n;i++){
if(p.at(i)==i+1){
s++;
i++;
}
}
cout << s << endl;
} |
#include<iostream>
using namespace std;
int main(void)
{
int n;
cin >> n;
int count=0;
for(int i=1;i<=n;i++)
{
int p;
cin >> p;
if(p==i)
{
count++;
cin >> p;
i++;
}
}
cout << count << endl;
} |
#include<iostream>
using namespace std;
long long p[100005];
int main(){
int n; cin >> n;
for(int i=1;i<=n;i++) cin >> p[i];
int cnt = 0;
for(int i=1;i<=n;i++){
if(p[i] == i){
cnt++;
swap(p[i],p[i+1]);
}
}
cout << cnt << endl;
return 0;
} |
#include <iostream>
using namespace std;
int main() {
int a;
cin >> a;
int b[a];
int c[a];
int ans = 0;
for (int i = 0;i < a;i++) {
cin >> b[i];
c[i] = b[i];
}
for (int i = 0;i < a - 1;i++) {
if (b[i] == i + 1) {
ans++;
b[i + 1] = b[i];
}
}
if (b[a - 1]== a) {ans++;}
cout << ans;
} |
#include <iostream>
using namespace std;
signed main()
{
int n;
cin >> n;
int in;
int ans = 0;
bool holding = false;
for (int i = 0; i < n; ++i)
{
cin >> in;
if (i + 1 == in && !holding)
{
++ans;
holding = true;
continue;
}
holding = false;
}
cout << ans << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
int N;
cin >> N;
vector<int> p(N);
for(int i = 0; i < N; i++){
cin >> p[i];
}
int cnt = 0;
for(int i = 0; i < N; i++){
if(p[i] == i + 1){
cnt++;
i++;
}
}
cout << cnt << endl;
}
|
#include <bits/stdc++.h>
#define N 100005
using namespace std;
int a[N];
int main(){
int n,count=0;
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
}
for(int i=1;i<=n;i++){
if(a[i]==i){
count++;
i++;
}
}
cout<<count<<endl;
return 0;
}
|
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
const int MX=2e5+9;
int n,x,ans,a[MX];
int main(){
cin>>n;
for(int i=1;i<=n;i++){
scanf("%d",&a[i]);
}
for(int i=1;i<=n+1;i++){
if(a[i]==i)x++;
else if(x){ans+=(x+1)/2;x=0;}
}
cout<<ans<<endl ;
}
|
#include <iostream>
using namespace std;
#define ll long long
int main () {
int n;
cin >> n;
int p[n];
for (int i = 0; i < n; i++) {
cin >> p[i];
p[i]--;
}
int ans = 0;
for (int i = 0; i < n; i++) {
if (i == p[i]) {
swap(p[i], p[i + 1]);
ans++;
}
}
cout << ans << endl;
} |
#include <iostream>
using namespace std;
int main() {
int N;
cin >> N;
int ans = 0;
for (int i = 1; i <= N; i++) {
int p;
cin >> p;
if (p == i) {
ans++;
if (i < N) {
cin >> p;
i++;
}
}
}
cout << ans << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
int main(void){
int N;
cin >> N;
vector<int> p(N);
for(int i = 0; i < N; i++) cin >> p[i];
int ans = 0;
for(int i = 0; i <= N-1; i++){
if(p[i] == i+1){
ans++;
i++;
}
}
cout << ans << endl;
} |
#include<iostream>
using namespace std;
int main() {
int N, p, ans = 0;
cin >> N;
for (int i = 1; i <= N; i++) {
cin >> p;
if (p == i) {
ans++; i++;
cin >> p;
}
}
cout << ans << endl;
} |
#include <iostream>
using namespace std;
const int MAXN = 100010;
int n;
int p[MAXN];
void solve() {
int cnt = 0;
for (int i=0;i<n;i++) {
if (i == p[i] - 1) {
swap(p[i], p[i+1]);
cnt++;
}
}
cout << cnt << endl;
}
int main() {
cin >> n;
for (int i=0;i<n;i++) {
cin >> p[i];
}
solve();
}
|
#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main ()
{
ll n,count=0,arr[100000];
cin>>n;
for(ll i=1;i<=n;i++)
cin >> arr[i];
for (ll i=1;i<=n;i++)
{
if (arr[i]==i)
{
count++;
if (i==n)
swap(arr[i],arr[i-1]);
else
swap(arr[i],arr[i+1]);
}
}
cout<<count;
} |
#include<iostream>
#include<algorithm>
using namespace std;
int n,a[100010],ans;
int main()
{
cin>>n;
for (int i=0;i<n;i++)
cin>>a[i];
for (int i=0;i<n;i++)
if (a[i]-1==i){
int t=a[i]+1;
a[i+1]=a[i];
a[i]=t;
ans++;
}
cout<<ans;
return 0;
} |
#include<iostream>
#include<vector>
using namespace std;
int main(){
int n;
cin>>n;
vector<int> p(n);
int ans=0;
for(int i=0;i<n;i++) cin>>p[i];
for(int i=0;i<n-1;i++){
if(p[i]==i+1){
swap(p[i],p[i+1]);
ans++;
}
}
if(p[n-1]==n) ans++;
cout<<ans<<endl;
} |
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
int main(){
ll n,ans=0;
cin >>n;
ll p[n];
for(ll i=0;i<n;i++) cin >>p[i];
for(ll i=0;i<n;i++){
if(p[i]==i+1) {
swap(p[i],p[i+1]);
ans++;
}
}
cout <<ans<<endl;
}
|
#include <bits/stdc++.h>
using namespace std;
int main() {
int N;
cin >> N;
int count = 0, ans = 0;
for (int i = 0; i < N; i++) {
int p;
cin >> p;
if (p == i + 1) {
count++;
}
else {
ans += count/2 + count%2;
count = 0;
}
}
ans += count/2 + count%2;
cout << ans << endl;
} |
#include <iostream>
using namespace std;
int n, p[100001], ans = 0;
int main() {
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> p[i];
}
for (int i = 1; i <= n; i++) {
if (p[i] == i) {
i++;
ans++;
}
}
cout << ans << endl;
} |
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+7;
int a[N];
map<int,int>mp;
int main()
{
int n;
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>a[i];
}
int ans=0;
for(int i=1;i<=n;i++)
{
if(a[i]==i)
{
ans++;
int temp=a[i];
a[i+1]=a[i];
a[i+1]=temp;
}
}
cout<<ans<<endl;
} |
#include<cstdio>
#define maxn 100010
int val[maxn];
int main(){
int n;
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%d",&val[i]);
}
int cnt=0;
for(int i=1;i<=n;i++){
if(i!=n&&val[i]==i&&val[i+1]==i+1){
cnt++;i++;
}
else if(val[i]==i)cnt++;
}
printf("%d",cnt);
} |
#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);i++)
using namespace std;
int main(){
int n; cin>>n;
int p[100000];
rep(i,n) cin>>p[i], p[i]--;
int cnt=0;
rep(i,n-1) if(p[i]==i) {
swap(p[i],p[i+1]);
cnt++;
}
if(p[n-1]==n-1) cnt++;
cout<<cnt<<endl;
return 0;
}
|
#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>
using namespace std;
int main(){
int n,c=0;
cin>>n;
int p[100000];
for(int i=0;i<n;i++)cin>>p[i];
for(int i=0;i<n;i++){
if(p[i]==i+1){
swap(p[i],p[i+1]);
c++;
}
}
cout<<c<<endl;
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
int main() {
int n; cin >> n;
vector<int> p(n);
for(auto&a:p) cin >> a,--a;
int ans=0;
for(int i=0;i<n;++i) {
if(p[i]==i) {
if(i==n) swap(p[i-1],p[i]);
else swap(p[i],p[i+1]);
++ans;
}
}
cout << ans << endl;
return 0;
}
|
#include <iostream>
#include <vector>
using namespace std;
int main(void){
int n;
cin >> n;
int p[n];
for(int i = 0; i < n; i++) cin >> p[i];
int ans = 0;
int i = 0;
while(i < n){
if(p[i] == i + 1){
ans++;
i += 2;
}else{
i++;
}
}
cout << ans << endl;
return 0;
}
|
#include <bits/stdc++.h>
using namespace std;
int main(){
int n;cin>>n;int ans=0;vector<int>x(n);
for(int i=0;i<n;++i)cin>>x[i];for(int i=0;i<n-1;++i)if(x[i]==i+1){swap(x[i],x[i+1]);++ans;}if(x[n-1]==n)++ans;
cout<<ans;cout<<endl;
return 0;} |
#include<bits/stdc++.h>
using namespace std;
int main() {
int n, arr[100010];
cin >> n;
for(int i = 0; i < n; i++) cin >> arr[i];
int dis = 0, con = 0;
for(int i = 0; i < n; i++) {
if(arr[i] == i+1) dis++;
if(i > 0 && arr[i] == i+1 && arr[i-1] == i) con++, arr[i]--;
}
cout << dis - con << endl;
}
|
#include <bits/stdc++.h>
using namespace std;
int N, P[100000];
int main(){
cin >> N;
for(int i=0;i<N;i++) cin >> P[i];
int ans = 0;
for(int i=0;i<N-1;i++){
if( P[i] == i+1 ){
swap(P[i], P[i+1]);
ans++;
}
}
if( P[N-1] == N ) ans++;
cout << ans << endl;
} |
#include<cstdio>
int n,s,a,i;
int main(){
scanf("%d",&n);
for(i=1;i<=n;i++){
scanf("%d",&a);
if(a==i){
s++;
scanf("%*d");
i++;
}
}
printf("%d",s);
}
|
#include <iostream>
using namespace std;
int main(){
int n;cin>>n;
int a[n];
for(int i = 0; n > i; i++){
cin>>a[i];
}
int ans = 0;
for(int i = 1; n >= i; i++){
if(a[i-1] == i){
swap(a[i-1],a[i]);ans++;
}
}
cout << ans << endl;
} |
#include<bits/stdc++.h>
using namespace std;
int N,p,f,ans;
int main(){
cin>>N;
for(int i{1};i<=N;++i){
cin>>p;
if(p==i&&!f)++ans,f=1;
else f=0;
}
cout<<ans<<endl;
}
|
#include <bits/stdc++.h>
using namespace std;
int main()
{
long long n,cnt=0;
cin>>n;
int ar[n];
for(int i=0;i<n;i++){
cin>>ar[i];
}
for(int i=0;i<n;i++){
if(ar[i]==i+1){
cnt++;
i++;
}
}
cout<<cnt;
} |
// D - Derangement
#include <bits/stdc++.h>
using namespace std;
#define rp(i,s,e) for(int i=(s);i<(e);++i)
int in(){int x;cin>>x;return x;}
int main(){
int N; cin>>N;
int L = in();
int ans = 0;
rp(i, 1, N){
int R = in();
if(L == i) ans++;
else L = R;
}
if(L == N) ans++;
cout<< ans <<endl;
} |
#include<bits/stdc++.h>
using namespace std;
int main(){
int N;
cin >> N;
vector<int>a(N);
for(int i=0;i<N;i++)
cin >> a.at(i);
int ans=0;
bool chen=false;
for(int i=0;i<N;i++){
if(a.at(i)==i+1&&!chen){
ans++;
chen=true;
}else{
chen=false;
}
}
cout << ans << endl;
return 0;
} |
#include <cstdio>
int a[100005];
int main() {
int n, ans = 0;
scanf("%d",&n);
for(int i = 1; i <= n; i++) scanf("%d", &a[i]);
for(int i = 1; i <= n; i++) {
if(a[i] == i) {
ans ++;
i ++;
}
}
printf("%d", ans);
} |
#include<iostream>
using namespace std;
int main()
{
int n,a[100005]={0},i,num=0;
cin >> n;
for(i=1;i<=n;i++)
cin>>a[i];
for(i=1;i<=n;i++)
{
if(a[i]==i)
{
num++;i++;
}
}
cout<<num<<endl;
return 0;
}
|
#include <iostream>
#include <vector>
#define REP(i, n) for(int i = 0; i < (n); i++)
using namespace std;
int main()
{
int N;
cin >> N;
vector<int> p(N);
REP(i, N) cin >> p[i];
int ans = 0;
REP(i, N) {
if (p[i] == i + 1) {
swap(p[i], p[i + 1]);
ans++;
}
}
cout << ans << endl;
return 0;
} |
#include<iostream>
using namespace std;
int a[100010];
int main()
{
int n,k=0,temp,c=0;
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>a[i];
if(a[i]!=i)
k++;
}
for(int i=1;i<=n;i++)
{
if(a[i]==i)
{
temp=a[i];
a[i]=a[i+1];
a[i+1]=temp;
c++;
}
}
if(k==n)
cout<<0<<endl;
else
cout<<c<<endl;
} |
#include<iostream>
using namespace std;
int main() {
int i, N;
int ans = 0;
bool *p;
cin >> N;
p = new bool[N];
for (i = 0; i < N; i++) {
int t;
cin >> t;
p[i] = t == i + 1;
}
for (i = 0; i < N; i++)
if (p[i]) {
if (p[i + 1]) i++;
ans++;
}
cout << ans << endl;
return 0;
} |
#include <bits/stdc++.h>
#define int long long
using namespace std;
int n,cnt=0;
int a[200005];
signed main()
{
cin>>n;
for (int i=1;i<=n;i++) cin>>a[i];
for (int i=1;i<=n-1;i++)
{
if (a[i]==i)
{
swap(a[i],a[i+1]);
cnt++;
}
}
if (a[n]==n) swap(a[1],a[n]),cnt++;
cout<<cnt<<endl;
return 0;
} |
#include <iostream>
#include <cstdio>
using namespace std;
int n, s, a[100005];
int main() {
int i;
scanf("%d", &n);
for(i=1; i<=n; i++) scanf("%d", &a[i]);
for(i=1; i<n; i++) if(a[i]==i) swap(a[i], a[i+1]), s++;
if(a[n]==n) s++;
cout<<s;
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
int main() {
int n;cin>>n;n=1;
int a,r=0;
while(cin>>a) {
if(n++ == a) {
r++;
n++;
cin>>a;
}
}
cout<<r<<endl;
} |
#include <iostream>
using namespace std;
int s[100001];
int ans;
int main(){
int a;
cin>>a;
for(int i=0;i<a;i++){
cin>>s[i];
if(s[i]==i+1)
s[i]=1;
else
s[i]=0;}
for(int i=0;i<a;i++){
if(s[i]==1)
{ans++;
if(s[i+1]==1)
s[i+1]=0;}}
cout<<ans;
return 0;
} |
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
int n; cin >> n;
vector<ll> p(n+1);
for(int i=1; i<=n; i++) cin >> p.at(i);
int cnt=0;
for(int i=1; i<n; i++){
if(p[i]!=i) continue;
swap(p[i], p[i+1]);
cnt += 1;
}
if(p[n]==n) cnt += 1;
cout << cnt << endl;
}
|
#include<iostream>
using namespace std;
int main(){
int N;
int p[100001]={};
int i;
int count = 0;
cin >> N;
for(i=1;i<N+1;i++)
cin >> p[i];
for(i=1;i<N+1;i++){
if(i == p[i]){
count++;
i++;
}
}
cout << count << endl;
return 0;
} |
#include<bits/stdc++.h>
using namespace std;
int main(){
int n,c,r=0;
cin>>n;
vector<int> v(n),u;
for(int i=0;i<n;++i){cin>>v[i];v[i]--;}
c=0;
for(int i=0;i<n;++i){
if(i-v[i]){
if(c)u.emplace_back(c);
c=0;
}
else c++;
}
if(c)u.emplace_back(c);
for(auto&& k:u)r+=k/2+k%2;
cout<<r;
} |
#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll a[100010];
int main(){
ll n,sum=0,max=0;cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
if(a[i]==i)sum++;
}
if(sum==0){
cout<<0;
return 0;
}
for(int i=1;i<=n;i++){
if(a[i]==i){
max++;
swap(a[i],a[i+1]);
}
}
cout<<max;
return 0;
} |
#include "bits/stdc++.h"
using namespace std;
const int N = 1e5 + 5;
int in[N];
int main() {
int n;
scanf("%d", &n);
for (int i = 1; i <= n; ++i) {
cin >> in[i];
}
int res = 0;
for (int i = 1; i <= n; ++i) {
if (in[i] == i) res++, i++;
}
cout << res << endl;
} |
#include <iostream>
using namespace std;
int main() {
int n; cin >> n;
int p[n];
for (int i = 0; i < n; i++) {
cin >> p[i]; p[i]--;
}
int ans = 0;
for (int i = 0; i < n-1; i++) {
if (p[i] == i) {
swap(p[i], p[i+1]);
ans++;
}
}
cout <<(p[n-1] == n-1 ? ans+1 : ans) << endl;
} |
#include <iostream>
using namespace std;
int main(void){
int n,a,w=0,ans=0;
cin>>n;
for(int i=1;i<=n;i++){
cin>>a;
if(a==i)w++;
if(a!=i || i==n){
ans+=(w+1)/2;
w=0;
}
}
cout<<ans<<endl;
}
|
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