Submission #992650

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Source Code Expand

#include <cstdio>
#include <iostream>
#include <cmath>
#include <cstring>
#include <sstream>
#include <algorithm>
#include <cstdlib>
#include <map>
#include <queue>
#include <utility>
#include <vector>
#include <set>
#include <memory.h>
#include <iomanip>
#include <bitset>
#include <list>
#include <stack>

using namespace std;

#define mod 1000000007

int main()
{
    int n, m;
    cin >> n >> m;
    vector<vector<int> > connection(200010);
    for(int i = 0; i < n; i++){
        int k;
        cin >> k;
        for(int j = 0; j < k; j++){
            int l;
            cin >> l;
            connection[l].push_back(i + 100001);
            connection[i + 100001].push_back(l);
        }
    }
    vector<bool> ischecked(200010, false);
    queue<int> qu;
    qu.push(100001);
    ischecked[100001] = true;
    while(!qu.empty()){
        int nownode = qu.front();
        qu.pop();
        for(int i = 0; i < connection[nownode].size(); i++){
            int nextnode = connection[nownode][i];
            if(ischecked[nextnode]) continue;
            ischecked[nextnode] = true;
            qu.push(nextnode);
        }
    }
    bool isallchecked = true;
    for(int i = 100001; i < 100001 + n; i++){
        if(!ischecked[i]){
            isallchecked = false;
            break;
        }
    }
    if(isallchecked) cout << "YES" << endl;
    else cout << "NO" << endl;
    return 0;
}

Submission Info

Judge Result