bin巨专题一 简单搜索（更新中

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 
 5 using namespace std;
 6 const int N = 20;
 7 
 8 int n, k, flag;
 9 char g[N][N];
10 bool row[N];
11 
12 void dfs(int u, int x){
13     if(x == k) {
14         flag ++;
15         return;
16     }
17     
18     for(int i = u; i < n ; i ++ ){
19         for(int j = 0; j < n; j ++ ){
20             if(g[i][j] != ‘.‘ && !row[j]){
21             row[j] = true;
22             dfs(i + 1, x + 1);
23             row[j] = false;
24             }
25         }
26     }
27     return;
28 }
29 
30 int main()
31 {
32     while(scanf("%d %d", &n, &k) != EOF){
33         if(n ==-1 && k == -1) break;
34         flag = 0;
35         for(int y = 0; y < n; y ++ )
36             for(int z = 0; z < n; z ++ )
37                 cin>>g[y][z];
38         dfs(0, 0);
39         printf("%d\n",flag);
40     }
41     return 0;
42 }