poj 3020（匈牙利算法+构图，无向二分图的最小路径覆盖 = 顶点数 – 最大二分匹配数/2）

#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
char c[45][15];
int data[45][15],count,M;
int edge[405][405],link[405],visit[405]; 
bool hungery(int m){
    for(int i=1;i<=count;i++){
        if(edge[m][i]&&!visit[i]){
            visit[i] = 1;
            if(link[i]==0||hungery(link[i])){
                link[i] = m;
                return true;
            }
        }
    }
    return false;
}
void search(){
    M = 0;
    for(int i=1;i<=count;i++){
        memset(visit,0,sizeof visit);
        if(hungery(i)){
            M++;
        }
    }
}
int main(){
    int n,h,w,i,j;
    scanf("%d",&n);
    while(n--){
        memset(edge,0,sizeof edge);
        memset(link,0,sizeof link);
        scanf("%d%d",&h,&w);
        count = 0;
        for(i=1;i<=h;i++){
            scanf("%s",c[i]);
            for(j=1;j<=w;j++){
                if(c[i][j-1]=='*')data[i][j] = ++count;
                else data[i][j] = 0;
            }
        }
        for(i=1;i<=h;i++){
            for(j=1;j<=w;j++){
                if(data[i][j]){
                    if(i+1<=h&&data[i+1][j]){
                        edge[data[i][j]][data[i+1][j]] = true;
                    }
                    if(i-1>0&&data[i-1][j]){
                        edge[data[i][j]][data[i-1][j]] = true;
                    }
                    if(j+1<=w&&data[i][j+1]){
                        edge[data[i][j]][data[i][j+1]] = true;
                    }
                    if(j-1>0&&data[i][j-1]){
                        edge[data[i][j]][data[i][j-1]] = true;
                    }
                }
            }
        }
        search();
        printf("%d\n",count-M/2); 
    }
    return 0;
}