rqnoj-331

ps:并查集，路径压缩.
学习资料：http://dongxicheng.org/structure/union-find-set/

#include<iostream>using namespace std;#define P 5001int father[5001],n,m,p;int Find_Set(int x){if(x != father[x])father[x] = Find_Set(father[x]);//递归压缩return father[x];}void Union(int x,int y){int a,b;a = Find_Set(x);b = Find_Set(y);if(a != b)father[a] = b;}int main(){int i,a,b;cin>>n>>m>>p;for(i = 1 ; i <= n ; i++)father[i]=i;for(i = 0 ; i < m ; i++){cin>>a>>b;Union(a,b);}for(i = 0 ; i < p ; i++){cin>>a>>b;if(Find_Set(a) == Find_Set(b))cout<<"Yes"<<endl;elsecout<<"No"<<endl;}return 0;}