poj dfs相关之1321 棋盘问题

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
int n, k, ans;
char space[8][8];
bool Colmark[8];
void dfs(int row, int res)
{
if (res == k)
{
ans++;
return;
}
int i, j;
for (i = row; i < n; i++)
{
for (j = 0; j < n; j++)
{
if (!Colmark[j] && space[i][j]=='#')
{
Colmark[j] = 1;
dfs(i + 1,res + 1);
Colmark[j] = 0;
}
}
}
}
int main()
{
freopen("1.txt", "r", stdin);
int i, j, sum;
while (scanf("%d%d", &n, &k) != EOF&&n != -1 && k != -1)
{
for (i = 0; i < n; i++)
{
scanf("%s", &space[i]);
}
ans = 0;
memset(Colmark, 0, sizeof(Colmark));
dfs(0, 0);
printf("%d\n", ans);
}
}