POJ 3020 Antenna Placement

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<vector>
#include<queue>
#include<cmath>
using namespace std;
#define INF 0x3fffffff
#define maxn 605
int n, CityNum, k, m;///重构图之后顶点的个数 OilNum
int Head[maxn];
int maps[maxn][maxn], P[maxn];
bool vis[maxn];
struct Node
{
    int e, next;
}edge[maxn*maxn];
void AddEdge(int s,int e)
{
    edge[k].next = Head[s];
    edge[k].e = e;
    Head[s] = k ++;
}

bool Find(int u)
{
    for(int i=Head[u]; i != -1; i = edge[i].next)
    {
        int v = edge[i].e;
        if(!vis[v])
        {
            vis[v] = true;
            if(P[v] == -1 || Find(P[v]))
            {
                P[v] = u;
                return true;
            }
        }
    }
    return false;
}

int solve()
{
    int ans = 0, ans2 = 0;
    memset(P, -1, sizeof(P));
    for(int i=1; i<=CityNum; i++)
    {
        memset(vis, false, sizeof(vis));
        if(Find(i))
            ans ++;
        else
            ans2 ++;
    }
    return ans / 2 + ans2;
}


int main()
{
    int T, cas = 1;
    char str[maxn];
    scanf("%d", &T);
    while(T--)
    {
        scanf("%d %d", &n, &m);

        k = CityNum = 0;
        memset(Head, -1, sizeof(Head));
        memset(maps, 0, sizeof(maps));

        for(int i=0; i<n; i++)///读入图，并且重新标记
        {
            scanf("%s", str);
            for(int j=0; j<m; j++)
            {
                if(str[j] == ‘o‘)
                    maps[i+1][j+1] = 0;
                if(str[j] == ‘*‘)
                    maps[i+1][j+1] = ++CityNum;
            }
        }

        for(int i=1; i<=n; i++)///重新构图
        {
            for(int j=1; j<=m; j++)
            {
                if(maps[i][j])
                {
                    if(maps[i-1][j])
                        AddEdge(maps[i][j], maps[i-1][j]);
                    if(maps[i+1][j])
                        AddEdge(maps[i][j], maps[i+1][j]);
                    if(maps[i][j-1])
                        AddEdge(maps[i][j], maps[i][j-1]);
                    if(maps[i][j+1])
                        AddEdge(maps[i][j], maps[i][j+1]);
                }
            }
        }

        printf("%d\n", solve());

    }
    return 0;
}

/*
3
1 0 1
1 0 1
0 1 0
*/