A1149 Dangerous Goods Packaging

#include<iostream>
#include<vector>
#include<map>
#include<string>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<set>
#include<queue>
#include<unordered_map>
#include<cmath>
using namespace std;
vector<int>v[1000001]; vector<int>v1;
int main()
{
	int n, m, t1, t2, q;
	cin >> n >> m;
	for (int i = 0; i < n; i++)
	{
		cin >> t1 >> t2;
		v[t1].push_back(t2);
		v[t2].push_back(t1);
	}
	for (int i = 0; i < m; i++)
	{
		cin >> q;
		v1.clear();
		int flag = 1;
		for (int j = 0; j < q; j++)
		{
			cin >> t1;
			v1.push_back(t1);
		}
		for (int j = 0; j < v1.size(); j++)
		{
			for (int q = 0; q < v[v1[j]].size(); q++)
			{
				if (find(v1.begin(), v1.end(), v[v1[j]][q]) != v1.end())
				{
					flag = 0;
					break;
				}	
			}
		}
		if (!flag)
		{
			cout << "No" << endl;
		}
		else
		{
			cout << "Yes" << endl;
		}
	}
}