Submission #1678321

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

int main(){
	int n,m; cin >> n >> m;
	vector<int> kl[n+m];
	for(int i = 0; i < n; ++i){
		int kmax; cin >> kmax;
		for(int j = 0; j < kmax; ++j){
			int lg; cin >> lg;
			kl[i].push_back(n-1+lg);
			kl[n-1+lg].push_back(i);
		}
	}
	
	vector<bool> visited(n+m,false);
	queue<int> npos;
	npos.push(0);
	visited[0] = true;
	int cost = 1;
	while(!npos.empty()){
		int now = npos.front();
		npos.pop();
		for(int i = 0; i < kl[now].size(); ++i){
			int next = kl[now][i];
			if(visited[next])continue;
			visited[next] = true;
			npos.push(next);
		}
		cost ++;
	}
	bool flag = true;
	for(int i = 0; i < n; ++i){
		if(!visited[i]){
			flag = false;
			break;
		}
	}

	if(flag) cout << "YES" << endl;
	else cout << "NO" << endl;

	return 0;
}

Submission Info

Judge Result