poj2524 Ubiquitous Religions

并查集模版题

#include<iostream>#include<cstring>#include<cstdio>using namespace std;int father[50005];int finds(int c){if(father[c]!=c)father[c]=finds(father[c]);return father[c];}void check(int a,int b){int aa=finds(a);int bb=finds(b);father[aa]=bb;}int main(){int n,m;int i;int a,b;int t=1;while(scanf("%d%d",&n,&m)){if(n==0&&m==0)break;for(i=1;i<=n;i++)father[i]=i;for(i=1;i<=m;i++){scanf("%d%d",&a,&b);check(a,b);}int sum=0;for(i=1;i<=n;i++)if(father[i]==i)sum++;printf("Case %d: %d\n",t,sum);t++;}return 0;}