poj 1321 DFS

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Description

Input

Output

Sample Input

2 1
#.
.#
4 4
...#
..#.
.#..
#...
-1 -1

Sample Output

2
1

Source

蔡错@pku

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<map>
#define INF 0x3f3f3f3f

using namespace std;

char a[10][10];
int hang[10],lie[10];//行标记,列标记
int n,m,lx,ly,num;
int DFS(int x,int y,int ans)
{
    if(ans==m)
    {
        num++;
        return 0;
    }
    for(int i=x; i<n; i++) //从x行开始遍历
    {
        if(hang[i])
            continue;
        for(int j=0; j<n; j++)
        {
            if(lie[j])
                continue;
            if(a[i][j]=='#')
            {
                hang[i]=1;
                lie[j]=1;
                DFS(i,j,ans+1);
                lie[j]=0;
                hang[i]=0;
            }
        }
    }
}
int main()
{
    while(~scanf("%d%d",&n,&m))
    {
        if(n==-1&&m==-1)
            break;
        int flag=1;
        memset(hang,0,sizeof(hang));
        memset(lie,0,sizeof(lie));
        for(int i=0; i<n; i++)
        {
            scanf("%s",a[i]);
        }
        num=0;
        DFS(0,0,0);
        printf("%d\n",num);
    }
}

poj 1321 DFS

标签：dfspan idtransmarksp   span idtransmarkspan   

原文地址：http://blog.csdn.net/became_a_wolf/article/details/47983321