POJ 1321 棋盘问题

1 #include <iostream>
2 #include <cstdio>
3 #include <cstdlib>
4 #include <cstring>
5 #include <cmath>
6
7 using namespace std;
8
9 int n,k,sum;
10
11 char map[10][10];
12
13 bool HashH[10],HashW[10];
14
15 void dfs(int h,int w,int kc)
16 {
17     int i,j;
18
19     if(kc == k)
20     {
21         ++sum;
22         return ;
23     }
24
25     for(i = h; i <= n; ++i)
26     {
27         for(j = (i == h ? w+1 : 1); j <= n; ++j)
28             if(map[i][j] == '#' && HashH[i] == false && HashW[j] == false)
29                 break;
30         if(j != n+1)
31             break;
32     }
33
34     if(map[i][j] == '#')
35     {
36         HashH[i] = true;
37         HashW[j] = true;
38         dfs(i,j,kc+1);
39         HashH[i] = false;
40         HashW[j] = false;
41         dfs(i,j,kc);
42     }
43 }
44
45 int main()
46 {
47     int i;
48     while(scanf("%d %d",&n,&k) && (n != -1 || k != -1))
49     {
50
51         sum = 0;
52
53         memset(HashH,false,sizeof(HashH));
54         memset(HashW,false,sizeof(HashW));
55
56         for(i = 1; i <= n; ++i)
57         {
58             scanf("%s",map[i]+1);
59         }
60
61         dfs(1,0,0);
62
63         printf("%d\n",sum);
64     }
65     return 0;
66 }