蓝桥题目：B-27、2n皇后问题

#include <iostream>
#include <cmath>
#include <cstring>
#define MAX 13//棋盘最大范围 
#define queen 2//两种棋 

using namespace std;

int N;
int rst = 0;
bool map[MAX][MAX];
int ans[queen][MAX];

bool check(int row, int column, int chess){
	if(map[row][column] == 1){
		for(int i = 0; i < chess; ++i){
			if(ans[i][row] == column){
				return 0;
			}
		}
		for(int i = 0; i < row; ++i){
			if(ans[chess][i] == column){//判断同列
				return 0;
			}
			if(abs(i - row) == abs(ans[chess][i] - column)){//判断对角线
				return 0;
			}
		}
		return 1;//能放
	}else{
		return 0;//不能放
	}
}

void dfs(int row, int chess){
	if(row == N){
		if(chess == queen-1){
			rst++;
			cout << rst << endl; 
		}else{
			dfs(0, chess + 1);
		}
	}
	for(int column = 0; column < N; ++column){
		if(!check(row, column, chess)){ 
			continue;
		}else{
			ans[chess][row] = column;//记录每种棋在每几行的列数
			dfs(row+1, chess);
		}
	}
}

int main(){
	cin >> N;
	for(int i = 0; i < N; ++i){
		for(int j = 0; j < N; ++j){
			cin >> map[i][j];
		}
	}
	dfs(0, 0);//第0种棋的第0行开始 
	cout << rst; 
	return 0;
}