#include<iostream>
using namespace std;

const int maxn=9;
char map[maxn][maxn];
int ans;
int n,k;
int visit[maxn];

void dfs(int x,int sum)
{
	if(sum==k){
		//cout<<"sum="<<sum<<" k="<<k<<endl;
		ans++;
		return;
	}
	if(x==n+1){
		//cout<<"sum="<<sum<<" k="<<k<<endl;
		if(sum==k)	ans++;
		return ;
	}
	for(int i=1;i<=n;i++){
		if(map[x][i]=='#'&&!visit[i]){
		//	cout<<"map["<<x<<"]["<<i<<"]"<<endl; 
			visit[i]=1;
			dfs(x+1,sum+1);
			visit[i]=0;
		}
	}
	dfs(x+1,sum);
}


int main()
{
	while(scanf("%d%d",&n,&k)!=EOF&&(n!=-1||k!=-1))
	{
		getchar();
		for(int i=1;i<=n;i++)
		{
			for(int j=1;j<=n;j++)
				scanf("%c",&map[i][j]);	
			getchar();
		}
				
		for(int i=1;i<=maxn;i++)	visit[i]=0;
		ans=0;
		
		dfs(1,0);
		printf("%d\n",ans);
	}
	
	return 0;
}

• Re:dfs一次过 (926) 2698022795 2019-09-27 21:33:04
  • Re:dfs一次过 (40) 2698022795 2019-09-27 21:34:59