Submission #11611118

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef pair<ll,ll> l_l;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
const int INF=1001001000;
const int mINF=-1001001000;
const ll LINF=1010010010010010000;
template<class T> inline bool chmin(T& a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T> inline bool chmax(T& a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
//グリッド：（典型）dp,dfs,bfs,最短経路,その他
struct UnionFind{
vector<int> par,depth,Size;
UnionFind(int n){
par.resize(n); depth.resize(n); Size.resize(n);
for(int i=0; i<n; i++){
par[i]=i;
depth[i]=0;
Size[i]=1;
}
}
int find(int x){
if(par[x]==x){
return x;
}
else{
return par[x]=find(par[x]);
}
}
bool same(int x, int y){
return find(x)==find(y);
}
void unite(int x, int y){
x=find(x); y=find(y);
if(x==y) return;
if(depth[x]<depth[y]) swap(x,y);
if(depth[x]==depth[y]) depth[x]++;
par[y]=x;
Size[x]+=Size[y];
}
int size(int x){
return Size[find(x)];
}
};
int main(){
    ll n,m;cin>>n>>m;
    UnionFind uf(220000);
    rep(i,n){
        ll k;cin>>k;
        rep(j,k){
            ll l;cin>>l;
            uf.unite(i+1,l+n);
        }
    }
    bool ok=true;
    rrep(i,n){
        if(!uf.same(1,i)) ok=false;
    }
    if(ok) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}

Submission Info

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