Submission #5425549

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Source Code Expand

#include <iostream>
#include <string>
#include <functional>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <math.h>
#include <map>

using namespace std;
using ll = long long;

int main()
{
	int n, m;
	cin >> n >> m;

	vector <vector <int> > adj(n + m);

	for (int i = 0; i < n; ++i)
	{
		int k;
		cin >> k;
		k;

		for (int j = 0; j < k; ++j)
		{
			int l;
			cin >> l;
			l--;
			adj[i].push_back(n + l);
			adj[n + l].push_back(i);
		}
	}

	stack<int> s;
	vector<bool>cat(n+m, false);


	s.push(0);
	cat[0] = true;

	while (!s.empty())
	{
		int oya = s.top();
		s.pop();

		for (int child : adj[oya])
		{
			if (!cat[child])
			{
				s.push(child);
				cat[child] = true;
			}
		}
	}

	bool flag = true;

	for (int i = 0; i < n; i++)
	{
		flag = flag && cat[i];
	}
	
	if (flag)
		cout << "YES" << endl;
	else
		cout << "NO" << endl;
	
	return 0;
}

Submission Info

Judge Result