hdu 2255 奔小康赚大钱

题目链接

Code:

#include <bits/stdc++.h>

using namespace std;


const int N=301;
int n;
int grid[N][N];
int expx[N];
int expy[N];
int matH[N];
int matP[N];
int visitedH[N];
int visitedP[N];
int sub;

bool dfs(int u){
    visitedP[u]=1;
    for(int i=0;i<n;++i){
        if(visitedH[i]) continue;
        int diff=expx[u]+expy[i]-grid[u][i];
        if(diff==0){
            visitedH[i]=1;
            if(matP[i]==-1 || dfs(matP[i])){
                matP[i]=u;
                matH[u]=i;
                return true;
            }
        }else{
            sub=min(sub,diff);
        }
    }
    return false;
}

int KM(){
    for(int i=0;i<n;++i){
        while(true){
            memset(visitedH,0,sizeof(visitedH));
            memset(visitedP,0,sizeof(visitedP));
            sub=INT_MAX;
            if(dfs(i)) break;

            for(int p=0;p<n;++p){
                if(visitedP[p]) expx[p]-=sub;
                if(visitedH[p]) expy[p]+=sub;
            }
        }
    }
    int res=0;
    for(int i=0;i<n;++i){
        int j=matH[i];
        res+=grid[i][j];
    }
    return res;
}

int main(){
    while(scanf("%d",&n)!=EOF){
        memset(matH,-1,sizeof(matH));
        memset(matP,-1,sizeof(matP));
        memset(visitedH,0,sizeof(visitedH));
        memset(visitedP,0,sizeof(visitedP));
        for(int i=0;i<n;++i){
            expx[i]=0;
            expy[i]=0;
            for(int j=0;j<n;++j){
                scanf("%d", &grid[i][j]);
                expx[i]=max(expx[i],grid[i][j]);
            }
        }
        int res=KM();
        printf("%d
",res);
    }
}