（并查集）The Suspects --POJ --1611

链接：

http://poj.org/problem?id=1611

http://acm.hust.edu.cn/vjudge/contest/view.action?cid=82830#problem/B

代码：

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
 
#define N 30005
 
int a[N];
int n, m;
 
int Find(int x)
{
    if(a[x]!=x)
        a[x] = Find(a[x]);
    return a[x];
}
 
int main()
{
 
    while(scanf("%d%d", &n, &m), n+m)
    {
        int p, px, py, s, x, y;
 
         for(int i=; i<=n; i++)
            a[i] = i;
 
        for(int i=; i<m; i++)
        {
            scanf("%d%d", &s, &x);
 
            for(int j=; j<s; j++)
            {
                scanf("%d", &y);
 
                px = Find(x);
                py = Find(y);
                if(px!=py)
                    a[py] = px;
            }
        }
        int sum=;
        p = Find();
 
         for(int i=; i<n; i++)
            if(Find(i)==p)
            sum++;
 
         printf("%d\n", sum);
 
    }
    return ;
}