1034.cpp

#include<iostream>
#include<cstring>
#include<fstream>
using namespace std;
int father[5100];
string p_save[5100];
int getfather(int n)
{
	if(father[n]==n) return n;
	father[n]=getfather(father[n]);
	return father[n];
}
int unionfather(int u,int v)
{
	int fu,fv;
	fu=getfather(u);
	fv=getfather(v);
	if(fu!=fv)
	  father[v]=father[u];
}
int main()
{
	int n,m,p;
	int a,b;
	ifstream fin("relation.in");
	fin >>n>>m>>p;
	int i;
	for(i=1;i<=n;i++)
	  father[n]=n;
	for(i=1;i<=m;i++)
	{
		fin >>a>>b;
		unionfather(a,b);
	}
	for(i=1;i<=p;i++)
	{
		fin >>a>>b;
		if(father[a]!=father[b])
		  p_save[i]="No";
		else p_save[i]="Yes"; 
	}
	fin.close();
	ofstream fout("relation.out");
	for(i=1;i<=p;i++)
	  fout <<p_save[i]<<endl;
	fout.close();
	return 0;
}