【並查集買一送一】Poj 2524——Ubiquitous Religions

來源：點擊開啟連結

更加標準的模板題，幾乎所有OIER和ACMER的培訓上都講過類似的例子，什麼配對強盜然後看分幾波。。配對敵人看看有幾方勢力。。配對物品發現有幾種。。之類的云云，一概屬於並查集。。。再去看看狀態壓縮。。ORORZ。。我看的課件是OIER的PAS版。。。。。。。。。。高中生IMBA

#include <cstring>#include <iostream>#include <stdio.h>using namespace std;int student[50005];int search(int tar){int result=tar;while(result!=student[result])result=student[result];return result;}void merge(int a,int b){int ka=search(a);int kb=search(b);if(ka!=kb){student[ka]=kb;}}int main(){int people,relation;int test=1;while(scanf("%d%d",&people,&relation) && (people!=0 ||relation!=0)){for(int k=0;k<=people;k++){student[k]=k;}int region=0;for(int i=1;i<=relation;i++){int a,b;scanf("%d%d",&a,&b);merge(a,b);}for(int j=1;j<=people;j++){if(student[j]==j)region++;}cout<<"Case "<<test<<": "<<region<<endl;test++;}return 0;}