POJ 1611

http://www.elijahqi.win/2017/07/11/poj-1611/
题目

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

模板题

#include<cstdio>
#define N 33000
int f[N],tmp1,tmp2,ans,n,m,k,s1,s2;
int gf(int x){
    return (x==f[x])?x:f[x]=gf(f[x]); 
}
int main(){
    freopen("poj1611.in","r",stdin);
    freopen("poj1611.out","w",stdout);
    while(1){
        scanf("%d%d",&n,&m);
        ans=0;
        if (n==0) break;
        for (int i=0;i<n;++i) f[i]=i;
        for (int i=1;i<=m;++i){
            scanf("%d",&k);
                scanf("%d",&s1);
            for (int i=2;i<=k;++i){
                scanf("%d",&s2);
                tmp1=gf(s1);tmp2=gf(s2);
                if (tmp1!=tmp2) f[gf(s1)]=tmp2;
            }
        }
        ans++;
        tmp1=gf(0);
        for (int i=1;i<n;++i) if (gf(i)==tmp1) ans++;
        printf("%d\n",ans);
    }
    return 0;
}