#include<iostream>
#define MAXN 5010
using namespace std;
int n,m,p,x,y;
int fa[MAXN];
int find(int x){
    if(x==fa[x]) return x;
    return fa[x]=find(fa[x]);   //路径压缩
}
void join(int c1,int c2){
    int f1=find(c1),f2=find(c2);
    if(f1!=f2) fa[f1]=f2;
}
int main(){
    cin>>n>>m>>p;
    for(int i = 1;i<=n;++i) fa[i]=i;    //初始化
    for(int i = 0;i<m;++i){
        cin>>x>>y;
        join(x,y);
    }
    for(int i = 0;i < p;++i){
        cin >> x >> y;
        if(find(x)==find(y))
            cout << "YES" << endl;
        else
            cout << "NO" << endl;
    }
    return 0;
}

样例

下载的测试用例