akbar.cpp

#include <bits/stdc++.h>
using namespace std;
 
#define REP(i, a, b) for (int i = a; i <= b; i++)
#define FOR(i, n) for (int i = 0; i < n; i++)
#define foreach(it, ar) for ( typeof(ar.begin()) it = ar.begin(); it != ar.end(); it++ )
#define fill(ar, val) memset(ar, val, sizeof(ar))
#define PI 3.1415926535897932385
#define uint64 unsigned long long
#define int64 long long
#define all(ar) ar.begin(), ar.end()
#define pb push_back
#define ff first
#define ss second
#define bit(n) (1<<(n))
#define Last(i) ( (i) & (-i) )
#define sq(x) ((x) * (x))
#define INF INT_MAX
#define maxN 1000000
#define  pb push_back
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef vector<int> vi;
typedef vector< vi > vvi ;
typedef long long ll ;
 
vector<int>visit(maxN, -1 ) ;
vvi g(maxN);
vi  val(maxN,-1);
bool flg = false;
 
void dfs(int vtx , int po ,int idx )
{
  // cout<<vtx<<" " <<idx	<<endl; 
   visit[vtx] = idx;
   
   if(po==0)return;
 
   for( int i = 0 ; i < g[vtx].size() ; i ++ )
     {
        int ch = g[vtx][i];
 
         if( visit[ch]  == - 1 )
            dfs( ch , po-1 , idx );
 
         else if( visit[ch] !=  idx )
                    flg = true ;
 
     }
}
 
 
int main()
 
{
  /*freopen("a.in", "r", stdin);
  freopen("a.out", "w", stdout);*/
 
  ios::sync_with_stdio(0);
  cin.tie(0);
  int t;
  cin>>t;
 
  while(t--)
    {
 
    int n , m  ,  k ;
       cin>> n >> m >> k ;
 
 
        int a, b;
       for( int i =  0 ; i < m ; i ++)
         {
 
            cin>>a>>b;
             --a;
             --b;
            g[a].pb(b);
            g[b].pb(a);
 
 
         }
 
           for( int i = 0  ; i < k ; i ++ )
               {
                 cin>>a>>b;
                  --a;
                 val[a] = b;
               }
 
        for(int i = 0 ; i  < n ; i ++)
          if( val[i]!=-1  )
             {
                if(visit[i]!=-1)
                    flg = true ;
                else  dfs(i,val[i],i);
               }
 
    /*   FOR(i,n)
           if(visit[i] == -1 )flg = true;*/
 
      if(flg)cout<<"No"<<endl;
      else cout<<"Yes"<<endl;
 
       FOR(i,n)
         {g[i].resize(0);
         visit[i] = -1;
         val[ i ] = -1; }
 
       flg = false;
 
    }
 }