题解 | #N皇后问题#

#include<iostream>
using namespace std;
int n;
int a[14];
int lie[14], zd[30], fd[30];
int ans = 0;

void dfs(int dep)
{
	if (dep > n)
	{
		ans++;

		return;
	}
	for (int i = 1; i <= n; i++)
	{
		if (lie[i] == 0 && zd[dep - i + n] == 0 && fd[dep + i] == 0)
		{
			a[dep] = i;
			lie[i] = 1; zd[dep - i + n] = 1; fd[dep + i] = 1;
			dfs(dep + 1);
			lie[i] = 0; zd[dep - i + n] = 0; fd[dep + i] = 0;
		}
	}
}

int main()
{
	cin >> n;
	dfs(1);
	cout << ans;
}