hdu 2120 Ice_cream's world I

就是问有多少个圈，简单的并查集，没啥好说的，心塞不开心

#include<iostream>using namespace std;int mapp[1000+5];void s(){for(int i=0;i<1000+5;i++) mapp[i]=i;}int bfs(int x){if(x!=mapp[x]){mapp[x]=bfs(mapp[x]);}return mapp[x];}int main(){int n,m;while(cin>>n>>m){s(); int sum=0;while(m--){int x,y;cin>>x>>y;x=bfs(x);y=bfs(y);if(x==y) sum++;else mapp[x]=y;}cout<<sum<<endl;}return 0;}