Submission #1402550

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Source Code Expand

#include <iostream>
#include <vector>
using namespace std;

bool used[100000],lused[100000];
vector<int> ls[100000],lang[100000];

void dfs(int v){
	used[v] = true;
	for(int i = 0;i < ls[v].size();i++){
		int l = ls[v][i];
		if(!lused[l]){
			for(int j = 0;j < lang[l].size();j++){
				int to = lang[l][j];
				if(!used[to]) dfs(to);
			}
		}
	}
}

int main(){
	int n,m;
	cin >> n >> m;
	for(int i = 0;i < n;i++){
		int k;
		cin >> k;
		for(int j = 0;j < k;j++){
			int l;
			cin >> l; l--;
			ls[i].push_back(l);
			lang[l].push_back(i);
		}
	}
	dfs(0);
	for(int i = 0;i < n;i++) {
		if(!used[i]){
			cout << "NO" << endl;
			return 0;
		}
	}
	cout << "YES" << endl;
	return 0;
}

Submission Info

Judge Result