Fire Net

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <algorithm>
 4 #include <cstring>
 5 
 6 using namespace std;
 7 
 8 /* run this program using the console pauser or add your own getch, system("pause") or input loop */
 9 //int main(int argc, char** argv) 
10 
11 #define N 1005
12 
13 struct node
14 {
15     int x, y;
16 }P[N][N];
17 
18 int x, y, n, g[N][N], used[N], vis[N], ans;
19 char s[N][N];
20 
21 int found(int u)
22 {
23     for(int i = 1; i <= y; i++)
24     {
25         if(!vis[i] && g[u][i])  // 可以放
26         {
27             vis[i] = 1;
28             if(!used[i] || found(used[i]))
29             {
30                 used[i] = u;
31                 return true;
32             }
33         }
34     }
35     return false;
36 }
37 
38 int main()
39 {    
40     while(scanf("%d", &n), n)
41     {
42         ans = x = y = 0;
43         memset(g, 0, sizeof(g));
44         memset(used, 0, sizeof(used));
45         
46         for(int i = 0; i < n; i++)
47             scanf("%s", s[i]);
48             
49         for(int i = 0; i < n; i++)
50         {
51             for(int j = 0; j < n; j++)
52             {
53                 if(s[i][j] == ‘.‘)
54                 {
55                     if(j == 0 || s[i][j-1] == ‘X‘)   // 前边是墙就可以另开一行或列放东西
56                         x++;
57                     P[i][j].x = x;
58                 }
59                 if(s[j][i] == ‘.‘)
60                 {
61                     if(j == 0 || s[j-1][i] == ‘X‘)
62                         y++;
63                     P[j][i].y = y;
64                 }
65             } 
66         }
67         
68         for(int i = 0; i < n; i++)
69         for(int j = 0; j < n; j++)
70         if(s[i][j] == ‘.‘)
71         g[P[i][j].x][P[i][j].y] = 1;  // 如果这个位置可以放东西，当前行列可以匹配
72         
73         for(int i = 1; i <= x; i++)
74         {
75             memset(vis, 0, sizeof(vis));
76             if(found(i))
77                 ans++;
78         }
79         
80         printf("%d\n", ans);
81     }
82     return 0;
83 }