HDU2255 奔小康赚大钱（km模板题）

/* ***********************************************
Author        :devil
Created Time  :2016/5/25 16:58:45
************************************************ */
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <cmath>
#include <stdlib.h>
using namespace std;
const int N=301;
const int inf=0x3f3f3f3f;
int w[N][N];
int lx[N],ly[N];
int link[N];
int visx[N],visy[N];
int slack[N];
int n;
bool dfs(int u)
{
    visx[u]=1;
    for(int v=1;v<=n;v++)
    {
        if(visy[v]) continue;
        int tmp=lx[u]+ly[v]-w[u][v];
        if(!tmp)
        {
            visy[v]=1;
            if(link[v]==-1||dfs(link[v]))
            {
                link[v]=u;
                return 1;
            }
        }
        else if(slack[v]>tmp) slack[v]=tmp;
    }
    return 0;
}
int km()
{
    memset(link,-1,sizeof(link));
    memset(ly,0,sizeof(ly));
    for(int i=1;i<=n;i++)
    {
        lx[i]=w[i][1];
        for(int j=2;j<=n;j++)
            lx[i]=max(lx[i],w[i][j]);
    }
    for(int x=1;x<=n;x++)
    {
        memset(slack,inf,sizeof(slack));
        while(1)
        {
            memset(visx,0,sizeof(visx));
            memset(visy,0,sizeof(visy));
            if(dfs(x)) break;
            int d=inf;
            for(int i=1;i<=n;i++)
                if(!visy[i]&&d>slack[i])
                    d=slack[i];
            for(int i=1;i<=n;i++)
            {
                if(visx[i]) lx[i]-=d;
                if(visy[i]) ly[i]+=d;
                else slack[i]-=d;
            }
        }
    }
    int ans=0;
    for(int i=1;i<=n;i++)
        if(link[i]>-1)
            ans+=w[link[i]][i];
    return ans;
}
int main()
{
    //freopen("in.txt","r",stdin);
    while(~scanf("%d",&n))
    {
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                scanf("%d",&w[i][j]);
        printf("%d\n",km());
    }
    return 0;
}