题目描述

样例

算法1

import java.util.Scanner;

public class Main {
    static int n;
    static char[][] g;
    static boolean[] col;
    static boolean[] dg;
    static boolean[] udg;

    public static void dfs(int u){
        if(u == n){
            for(int i=0;i<n;i++){
                for(int j = 0;j<n;j++){
                    System.out.print(g[i][j]);
                }
                System.out.println();
            }
            System.out.println();
            return;
        }
        for(int i=0;i< n;i++){
            if(!col[i] && !dg[i+u] && !udg[i -u+n-1]) {
                g[u][i] = 'Q';
                col[i] = true;
                dg[u+i] = true;
                udg[i-u+n-1] = true;
                dfs(u+1);
                col[i] = false;
                dg[u+i] = false;
                udg[i-u+n-1] = false;
                g[u][i] = '.';

            }
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        g = new char[n][n];
        col = new boolean[n];
        dg = new boolean[2*n-1];
        udg = new boolean[2*n-1];
        for(int i = 0;i<n;i++){
            for(int j = 0;j<n;j++){
                g[i][j] = '.';
            }
        }
        dfs(0);
    }
}