思路是对的啊，数据也是够的，不知道为啥全爆了

#include<bits/stdc++.h>
using namespace std;
const int maxn = 5005;
int f[maxn];
int find(int x){return f[x]==x?x:f[x] = find(f[x]);}
int main(){
	int n,m,p;
	cin>>n>>m>>p;
	for(int i = 1;i<=n;i++){
		f[i] = i;
	}
	for(int i = 1;i<=m;i++){
		int x,y;
		cin>>x>>y;
		f[find(x)] = find(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;
}