1 #include<iostream> 2 #include<string.h> 3 #include<stdio.h> 4 using namespace std; 5 int n,m,cnt; 6 bool column[10]; 7 char f[10][10]; 8 void dfs(int step,int t) 9 { 10 if(t>m) 11 { 12 ++cnt; 13 return; 14 } 15 if(step>n)return; 16 for(int i=1;i<=n;++i) 17 if(!column[i] && f[step][i]=='#') 18 { 19 column[i]=1; 20 dfs(step+1,t+1); 21 column[i]=0; 22 } 23 dfs(step+1,t); 24 } 25 int main() 26 { 27 // freopen("board.in","r",stdin); 28 // freopen("board.out","w",stdout); 29 while(~scanf("%d%d",&n,&m)) 30 { 31 if(n==-1 && m==-1) break; 32 if(m>n) 33 { 34 printf("0"); 35 continue; 36 } 37 for(int i=1;i<=n;++i) 38 for(int j=1;j<=n;++j) 39 cin>>f[i][j]; 40 cnt=0; 41 memset(column,0,sizeof(column)); 42 dfs(1,1); 43 printf("%d ",cnt); 44 } 45 } 46 /* 47 2 1 48 #. 49 .# 50 4 4 51 ...# 52 ..#. 53 .#.. 54 #... 55 -1 -1 56 */