hdu 2063

简单二分图匹配；熟悉“匈牙利算法”后，基本上套模板就出来了;

这个博客讲匈牙利算法挺有意思的，可以参考一下;

点击打开链接

//二分图匹配, 匈牙利算法;
#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int k, m, n;
int cnt;
struct Edge{
    int to, next;
}edge[1005];
int inpath[1005], match[1005], head[1005];

void addEdge(int u, int v){
    edge[cnt].to = v;
    edge[cnt].next = head[u];
    head[u] = cnt++;
}
int findpath(int);
int hungary(){
    int ans = 0;
    memset(match, -1, sizeof(match));
    memset(inpath, 0, sizeof(inpath));
    for(int i = 1; i <= m; ++i){
        if(findpath(i)){
            ans++;
        }
    }
    return ans;
}
int findpath(int u){
    for(int i = head[u]; ~i; i = edge[i].next){
        int v = edge[i].to;
        if(!inpath[v]){
            inpath[v] = 1;
            if(match[v] == -1 || findpath(match[v])){
                match[v] = u;
                inpath[v] = 0;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    while(scanf("%d", &k) != EOF && k){
        scanf("%d%d", &m, &n);
        cnt = 0;
        memset(head, -1, sizeof(head));
        int u, v;
        for(int i = 0; i < k; ++i){
            scanf("%d%d", &u, &v);
            addEdge(u, v);
        }
        int ans = hungary();
        printf("%d\n", ans);
    }
}