poj2524（简单并查集）

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
using namespace std;
int n,m;
int bin[50001];
int findx(int x)
{
    int r=x;
    while(r!=bin[r])
        r=bin[r];
    int j=x,k;
    while(j!=r)
    {
        k=bin[j];
        bin[j]=r;
        j=k;
    }
    return r;
}
void merge(int x,int y)
{
    int fx=findx(x);
    int fy=findx(y);
    if(fx!=fy)
        bin[fy]=fx;
}
int main()
{
    int x,y,k=0;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        k++;
        if(n==0&&m==0) break;
        for(int i=0;i<=n;i++)
            bin[i]=i;
        while(m--)
        {
           scanf("%d%d",&x,&y);
           merge(x,y);
        }
        int sum=0;
        for(int i=1;i<=n;i++)
            if(bin[i]==i)
            sum++;
        printf("Case %d: %d\n",k,sum);

    }
    return 0;
}

来源：https://www.cnblogs.com/zhangmingcheng/p/3786100.html