kuangbin帶你飛 專題1棋盤問題

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std; 
int n, k, ans;
char s[100][100];
int col[10]; 
void dfs(int x,int t)
{	
  if (x == n)	
  {		
   if (t == k)			
   ans++;		
  return;	
  } 	
  for (int i = 0; i < n; i++)	
  {		
   if (s[x][
 
i] == '#'&&col[i] == 0)		
   {			
    col[i] = 1;			
    dfs(x + 1, t + 1);			
    col[i] = 0;		
   }	
  }	
   dfs(x + 1, t);
} 
int main()
{	
   cin >> n >> k;	
   while (n != -1 && k != -1)	
   {				
    for (int i = 0; i < n; i++) cin >> s[i]; 		
    ans = 0;		
    dfs
 
(0, 0);		
    cout << ans << endl;		
    cin >> n >> k;	
   } 	
   return 0;
}