AKBAR.cpp

/*

Author : @karngyan

*/


#include<bits/stdc++.h>
using namespace std;

using ll = long long;
using vll = std::vector< ll >;

const ll N = 1e6+2;
vll g[N];
vll god;
ll n , r, m;


bool bfs(ll source_node , ll strength){
	ll level = 1;
	if(god[source_node] != -1){
		return false;
	}

	vll all;
	all.push_back(source_node);
	god[source_node] = source_node;

	while(level <= strength){
		vll new_all;
		for(auto it : all){
			for(auto y : g[it]){
				if(god[y] == -1){
					god[y] = source_node;
					new_all.push_back(y);
				}
				else if(god[y] == source_node)
					continue;
				else
					return false;
			}
		}

		all = new_all;
		level++;
	}

	return true;
}

int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);


	ll t;
	cin >> t;
	while(t--)
	{
		cin >> n >> r >> m;
		god.clear();
		god.resize(n+1 , -1);
		for(int i = 0 ; i<= n ; ++i){
			g[i].clear();
		}

		for(int i = 0 ; i < r ; ++i){
			ll u , v;
			cin >> u >> v;
			g[u].emplace_back(v);
			g[v].emplace_back(u);
		}
		
		string ans = "Yes";

		for(int i = 0 ; i<m ; ++i){
			ll k , s;
			cin >> k >> s;
			bool check = bfs(k , s);
			if(!check){
				ans = "No";
				break;
			}
		}

		// given in question that each node should have exactly one god
		for(ll i =1 ; i<=n ; ++i){
			if(god[i] == -1){
				ans = "No";
				break;
			}
		}
		cout << ans << "\n";
	}
	return 0;
}