> #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 (40) 2698022795 2019-09-27 21:34:59