Codeforces Round #170 (Div. 1)A

//用并查集记录有几个集合，然后将总的集合数剪一即为所求答案

//注意一下全0就行

#include<cstdio>

#include<cstring>

#include<iostream>

using namespace std ;

const int maxn = 110 ;

int map[maxn][maxn] ;

int F[maxn] ;

int n , m ;

int find(int x)

{

if(F[x] == x)

return F[x] ;

return F[x] = find(F[x]) ;

}

void join(int x , int y)

{

int fx = find(x) ;

int fy = find(y) ;

if(fx != fy)

F[fx] = fy ;

}

int main()

{

while(~scanf("%d %d" ,&n , &m))

{

memset(map , 0 ,sizeof(map)) ;

for(int i = 1;i <= n;i++)

F[i] = i;

int tag = 0 ;

for(int i = 1;i <= n;i++)

{

int num ;

scanf("%d" ,&num) ;

if(num)tag = 1;

while(num--)

{

int a;

scanf("%d" ,&a) ;

map[i][a] = 1;

}

}

if(!tag){printf("%d\n" ,n);continue ;}

for(int j = 1;j <= m;j++)

{

int flag = 0 ;

for(int i = 1;i <= n;i++)

if(map[i][j])

{

if(!flag)

flag = i;

else join(flag , i) ;

}

}

int temp[maxn] ;

int j = 0;int k;

for(int i = 1;i <= n;i++)

{

for(k = 0;k < j;k++)

if(temp[k] == find(i))

break;

if(k == j)

temp[j++] = find(i);

}

printf("%d\n" , j  - 1) ;

}

return 0;

}