点击此处打开原题链接：https://vijos.org/p/1034

附AC代码：

#include<stdio.h>
#define M 50001
int father[M],a,b,m,n,p;
int find(int x){
    if (father[x]!=x) father[x]=find(father[x]);
    return father[x];
}
int main(){
	int i;
    scanf("%d%d%d",&n,&m,&p);
    for (i=1;i<=n;i++) father[i] = i;
    for (i=1;i<=m;i++){
        scanf("%d%d",&a,&b);
        a=find(a),b=find(b);father[a]=b;
    }
    for(i=1;i<=p;i++){
        scanf("%d%d",&a,&b);
        a=find(a);b=find(b);
        if(a==b)printf("Yes\n");else printf("No\n");
    }
    return 0;
}