题解

#include<bits/stdc++.h>
using namespace std;
const int N=100001;
int a[N];
int find(int x){
	if(x==a[x]){
		return x;
	}
	else return a[x]=find(a[x]);
}
void join(int x,int y){
	int xx=find(x);
	int yy=find(y);
	if(xx!=yy) a[xx]=yy;
}
int main(){
	int n,m,p;
	cin>>n>>m>>p;
	for(int i=1;i<=n;i++){
		a[i]=i;
	}
	for(int i=1;i<=m;i++){
		int x,y;
		cin>>x>>y;
		join(x,y);
	}
	for(int i=1;i<=p;i++){
		int x,y;
		cin>>x>>y;
		if(find(x)==find(y)) cout<<"Yes"<<endl;
		else cout<<"No"<<endl;
	}
	return 0;
}