POJ - 1321 深度优先搜索入门

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
int book[],n,m,o;
char map[][];
void dfs(int num,int y){
    if(num==m){
        o++;
        return ;
    }
    if(y>n)
    return ;
    for(int i=;i<=n;i++){
        if(map[y][i]=='#'&&book[i]==){
            book[i]=;
            dfs(num+,y+);
            book[i]=;
        }
    }
    dfs(num,y+);
}
int main(){
        while(cin>>n>>m&&(n!=-||m!=-)){
            o=;
            memset(book,,);
            for(int i=;i<=n;i++)
                for(int j=;j<=n;j++)
                    cin>>map[i][j];
            dfs(,);
            cout<<o<<endl;
        }

    return ;
}