poj1611解题报告

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
using namespace std ;

const int MAXN = 30005 ;

int   father[MAXN] ;

int   find( int x )
{
if( father[x] != x ) father[x] = find( father[x] ) ;
return father[x] ;
}

void  Union( int a , int b )
{
int  f1 = find( a ) ;
int  f2 = find( b ) ;
if( f1 != f2 ) father[f2] = f1 ;
}

int  main()
{
int   n , m , num , student[MAXN] , Count ;

while( scanf( "%d%d" , & n , & m ) && n )
{
Count = 1 ;
for( int i = 0 ; i <= n ; i ++ ) father[i] = i ;

while( m -- )
{
scanf( "%d" , & num ) ;
for( int i = 0 ; i < num ; i ++ )
scanf( "%d" , & student[i] ) ;

for( int i = 1 ; i < num ; i ++ )
Union( student[0] , student[i] ) ;

}

int  temp = find( 0 ) ;

for( int i = 1 ; i < n ; i ++ ){
if( find( i ) == temp ) Count ++ ;
}

printf( "%d\n" , Count ) ;
}

return 0 ;
}