HDU 4185 Oil Skimming

#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, OilNum, k;///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];
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;
memset(P, -1, sizeof(P));
for(int i=1; i<=OilNum; i++)
{
memset(vis, false, sizeof(vis));
if(Find(i))
ans ++;
}
return ans / 2;
}

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

k = OilNum = 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<n; j++)
{
if(str[j] == '.')
maps[i+1][j+1] = 0;
if(str[j] == '#')
maps[i+1][j+1] = ++OilNum;
}
}

for(int i=1; i<=n; i++)///重新构图
{
for(int j=1; j<=n; 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("Case %d: %d\n", cas ++,solve());

}
return 0;
}

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