Submission #1006850

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <string>
#include <set>
#include <cmath>
#include <map>
#define rep(i,n) for(int i=0;i<n;++i)
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define maxn 300000
int par[maxn];
int size[maxn];
void init(int n){
    rep(i,n){
        size[i]=1;
        par[i]=i;
    }
}
int find(int x){
    if(x==par[x])return x;
    return par[x]==find(par[x]);
}
void unite(int x,int y){
    x = find(x);
    y = find(y);
    if(x==y)return;
    if(size[x]<size[y])swap(x,y);
    par[y]=x;
    size[x]+=size[y];
}
bool same(int x,int y){
    return find(x) == find(y);
}
int main(){
    int n,m;
    cin >> n >> m;
    int k;
    int l;
    init(maxn-1);
    rep(i,n){
        cin >> k;
        rep(j,k){
            cin >> l;
            unite(i,l+1e5+1);
        }
    }
    int hoge = find(1);
    //cout << hoge << endl;
    for(int i=1;i<n-1;i++){
        if(find(i)!=hoge) {
            cout << "NO" << endl;
            cout << i << endl;
            return 0;
        }
    }
    cout << "YES" << endl;
    return 0;
}

Submission Info

Judge Result