2 분 일치 하 는 Hopcroft - Carp 알고리즘

#include <stdio.h>
#include <iostream>
#include <string.h>
#include <queue>

const int N=1005;
const int INF=1<<28;

int g[N][N];
int Mx[N];
int My[N];
int dx[N];
int dy[N];
bool used[N];

int Nx,Ny,dis;

bool searchP()
{
    dis=INF;
    int i,v,u;
    std::queue<int> Q;

    memset(dx,-1,sizeof(dx));
    memset(dy,-1,sizeof(dy));
    for(i=0;i<Nx;i++)
    {
        if(Mx[i]==-1)
        {
            Q.push(i);
            dx[i]=0;
        }
    }
    while(!Q.empty())
    {
        u=Q.front();
        Q.pop();
        if(dx[u]>dis) break;
        for(v=0;v<Ny;v++)
        {
            if(g[u][v]&&dy[v]==-1)
            {
                dy[v]=dx[u]+1;
                if(My[v]==-1) dis=dy[v];
                else
                {
                    dx[My[v]]=dy[v]+1;
                    Q.push(My[v]);
                }
            }
        }
    }
    return dis!=INF;
}

bool DFS(int u)
{
    int v;
    for(v=0;v<Ny;v++)
    {
        if(g[u][v]&&!used[v]&&dy[v]==dx[u]+1)
        {
            used[v]=true;
            if(My[v]!=-1&&dy[v]==dis) continue;
            if(My[v]==-1||DFS(My[v]))
            {
                My[v]=u;
                Mx[u]=v;
                return true;
            }
        }
    }
    return false;
}

int Hungary()
{
    int u;
    int ret=0;
    memset(Mx,-1,sizeof(Mx));
    memset(My,-1,sizeof(My));
    while(searchP())
    {
        memset(used,false,sizeof(used));
        for(u=0;u<Nx;u++)
           if(Mx[u]==-1&&DFS(u))  ret++;
    }
    return ret;
}

int main()
{
    int k,u,v;
    while(~scanf("%d",&k),k)
    {
        scanf("%d%d",&Nx,&Ny);
        memset(g,0,sizeof(g));
        Ny=Nx>Ny? Nx:Ny;
        while(k--)
        {
            scanf("%d%d",&u,&v);
            u--;v--;
            g[u][v]=1;
        }
        int ans=Hungary();
        printf("%d
",ans);
    }
    return 0;
}