带权二分图的最大权匹配 KM算法模版

下面是kuangbin大神的模版，已通过西电oj1048的测试

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<string>
#include<math.h>
#include<cctype>

using namespace std;

typedef long long ll;
const int maxn=550;
const int INF=(1<<29);
const double EPS=0.0000000001;
const double Pi=acos(-1.0);

int G[maxn][maxn];
int m;
int nx,ny;
int link[maxn],lx[maxn],ly[maxn];
int slack[maxn];
bool visx[maxn],visy[maxn];

bool dfs(int x)
{
    visx[x]=1;
    for(int y=0;y<ny;y++){
        if(visy[y]) continue;
        int tmp=lx[x]+ly[y]-G[x][y];
        if(tmp==0){
            visy[y]=1;
            if(link[y]==-1||dfs(link[y])){
                link[y]=x;
                return true;
            }
        }
        else if(slack[y]>tmp) slack[y]=tmp;
    }
    return false;
}

int KM()
{
    memset(link,-1,sizeof(link));
    memset(ly,0,sizeof(ly));
    for(int i=0;i<nx;i++){
        lx[i]=-INF;
        for(int j=0;j<ny;j++){
            if(G[i][j]>lx[i]) lx[i]=G[i][j];
        }
    }
    for(int x=0;x<nx;x++){
        for(int i=0;i<ny;i++) slack[i]=INF;
        while(1){
            memset(visx,0,sizeof(visx));
            memset(visy,0,sizeof(visy));
            if(dfs(x)) break;
            int d=INF;
            for(int i=0;i<ny;i++){
                if(!visy[i]&&d>slack[i]) d=slack[i];
            }
            for(int i=0;i<nx;i++){
                if(visx[i]) lx[i]-=d;
            }
            for(int i=0;i<ny;i++){
                if(visy[i]) ly[i]+=d;
                else slack[i]-=d;
            }
        }
    }
    int res=0;
    for(int i=0;i<ny;i++){
        if(link[i]!=-1) res+=G[link[i]][i];
    }
    return res;
}

int main()
{
    while(cin>>nx>>ny){
        memset(G,0,sizeof(G));
        cin>>m;
        while(m--){
            int u,v;
            scanf("%d%d",&u,&v);
            G[u][v]=1;
        }
        cout<<KM()<<endl;
    }
    return 0;
}