Treasure Exploration POJ - 2594

#include<stdio.h>
#include<string.h>
#include<queue>
#include<algorithm>
using namespace std;
#define N 510
int vis[N], match[N], maps[N][N], n, ans;
void floyd()
{
    for(int k=1; k<=n; k++)
        for(int i=1; i<=n; i++)
            for(int j=1; j<=n; j++)
                if(maps[i][k] && maps[k][j])
                    maps[i][j] = 1;
}
bool Find(int u)
{
    for(int i=1; i<=n; i++)
    {
        if(!vis[i] && maps[u][i])
        {
            vis[i] = 1;
            if(!match[i] || Find(match[i]))
            {
                match[i] = u;
                return true;
            }
        }
    }
    return false;
}
int main()
{
    int a, b, m;
    while(scanf("%d%d", &n, &m), m+n)
    {
        memset(maps, 0, sizeof(maps));
        for(int i=0; i<m; i++)
        {
            scanf("%d%d", &a, &b);
            maps[a][b]  = 1;
        }
        floyd();
        ans = 0;
        memset(match, 0, sizeof(match));
        for(int i=1; i<=n; i++)
        {
            memset(vis, 0, sizeof(vis));
            if(Find(i))
                ans++;
        }
        printf("%d\n", n - ans);
    }
    return 0;
}

Treasure Exploration POJ - 2594

原文：https://www.cnblogs.com/QingyuYYYYY/p/12431059.html