POJ 2771 Guardian of Decency（最大独立点集）

把有可能在一起的连边，求最大独立点集

代码：

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

const int N = 550;
struct pupils {
    int h;
    string sex;
    string music;
    string sport;
}P[N];
int T, n;
int bmap[N][N], cy[N];
bool vis[N];

bool dfs( int u ) 
{
    for ( int v = 1; v <= n; ++v ) if ( bmap[u][v] && !vis[v] ) {
        vis[v] = 1;
        if ( cy[v] == -1 || dfs(cy[v])) {
            cy[v] = u;
            return 1;
        }
    }
    return 0;
}
int match()
{
    int res = 0;
    memset( cy, -1, sizeof(cy) );
    for ( int i = 1; i <= n; ++i ) {
        memset( vis, 0, sizeof(vis));
        if ( dfs(i)) res++;
    }
    return res;
}
int main()
{
    scanf("%d", &T);
    while ( T-- ) {
        scanf("%d", &n);
        for ( int i = 1; i <= n; ++i ) {
            cin >> P[i].h >> P[i].sex >> P[i].music >> P[i].sport;
            //cout << P[i].h << " " << P[i].sex << " "  << P[i].music << " "  << P[i].sport << endl;
        }
        memset( bmap, 0, sizeof(bmap));
        for ( int i = 1; i <= n; ++i ) 
            for ( int j = 1+i; j <= n; ++j ) if ( abs(P[i].h-P[j].h) <= 40 && P[i].sex != P[j].sex && P[i].music == P[j].music && P[i].sport != P[j].sport ) 
                bmap[i][j] = bmap[j][i] = 1;
        printf("%d\n", n-match()/2);
    }
}