杭电2064----过山车『匈牙利算法』

//匈牙利算法模版题
#include <cstdio>
#include <vector>
#include <cstring>
using namespace std;
const int maxn = 505;
vector<int> v[maxn];
int vis[maxn],match[maxn];
bool dfs(int t)
{
    for(int i = 0; i < v[t].size(); ++i)
    {
        int x = v[t][i];
        if(!vis[x])
        {
            vis[x] = 1;
            if(match[x] == -1 || dfs(match[x]))
            {match[x] = t; return true; }
        }
    }
    return false;
}
int hungary(int n)
{
    int ans = 0;
    for(int i = 1; i <= n; ++i)
    {
        memset(vis,0,sizeof vis);
        if(dfs(i)) ++ans;
    }
    return ans;
}
int main()
{
    int k,n,m,x,y;
    while(~scanf("%d",&k) && k)
    {
        scanf("%d%d",&n,&m);
        for(int i = 1; i <= n; ++i)
            v[i].clear();
        memset(match,-1,sizeof match);
        while(k--)
        {
            scanf("%d%d",&x,&y);
            v[x].push_back(y);
        }
        printf("%d\n",hungary(n));
    }
    return 0;
}