HDU OJ 5326 Work( 2015多校联合训练第3场) 并查集

　题目连接：戳ME

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
const int M = 1e2+5;
int n, k;
int par[M];
int sum[M];

void find(int x)
{
    if( par[x]!=x )
    {
        sum[par[x]]++;
        find(par[x]);
    }
    else
        return;
}
int main()
{
    while( ~scanf("%d %d", &n, &k ) )
    {
        memset( par, 0, sizeof(par) );
        memset( sum, 0, sizeof(sum) );
        for( int i=1; i<=n; i++ )
            par[i] = i;
        for( int i=1; i<n; i++ )
        {
            int x, y;
            scanf("%d %d", &x, &y );
            par[y] = x;
        }
        for( int i=1; i<=n; i++ )
            find( i );
        int ret = 0;
        for( int i=1; i<=n; i++ )
        {
            if( sum[i]==k )
                ret++;
        }
        printf("%d\n", ret );
    }

}