题解 | #八皇后#

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;

int n;
string res[100];
int index = 0;
bool isused[8][8] = { false };
bool col[8];

bool check(int x, int y) {
	int y1 = y;
	for (int i = x; i >= 0; i--) {
		if (y >= 0 && isused[i][y--] == true)
			return true;
		if (y1 < 8 && isused[i][y1++] == true)
			return true;
	}
	return false;
}


void DFS(int position, string str) {

	if (position == 8) {
		res[index++] = str;
		return;
	}
	for (int j = 0; j < 8; j++) {
		if (check(position, j) || col[j] == true) {  //检查对角线上是否有结点
			continue;
		}
		col[j] = true;
		isused[position][j] = true;
		char s = j + '0'+1;
		DFS(position + 1, str+s);
		col[j] = false;
		isused[position][j] = false;
	}
}


int main() {
	DFS(0,"");
	sort(res, res + 92);
	while (cin >> n) {

		cout << res[n-1]<<endl;

	}
}