HDU 2063 过山车

#include <bits/stdc++.h>
using namespace std;

const int maxn = 2010;
int K, M, N;
int mp[1010][1010];
int vis[maxn], match[maxn];

bool path(int u) {
    for(int v = 1; v <= N; v ++) {
        if(mp[u][v] && !vis[v]) {
            vis[v] = 1;
            if(match[v] == -1 || path(match[v])) {
                match[v] = u;
                return true;
            }
        }
    }
    return false;
}

int main() {
    while(~scanf("%d", &K)) {
        if(!K) break;
        memset(match, -1, sizeof(match));
        memset(mp, 0, sizeof(mp));
        scanf("%d%d", &M, &N);
        while(K --) {
            int x, y;
            scanf("%d%d", &x, &y);
            mp[x][y] = 1;
        }
        int cnt = 0;
        for(int i = 1; i <= M; i ++) {
            memset(vis, 0, sizeof(vis));
            if(path(i))
                cnt ++;
        }
        printf("%d\n", cnt);
    }
    return 0;
}