蒟蒻求调整代码

import java.io.BufferedInputStream;
import java.util.*;

public class P1219 {
    static int N = 20;
    static int n;
    static int[][] g = new int[N][N];
    static boolean[] row = new boolean[100];
    static boolean[] col = new boolean[100];
    static boolean[] dg = new boolean[100];
    static boolean[] udg = new boolean[100];
    static int cnt = 0; // 用来记载解的次数
    static List<int[]> ans = new ArrayList<>();
    static void dfs(int x,int y,int s) {
        if (y == n) {
            x ++;
            y = 0;
        }
        if (x == n) {
            if (s == n) {
                int[] mark = new int[n];
                int idx = 0;
                cnt ++;
                for (int i = 0; i < n; i++) {
                    for (int j = 0; j < n; j++) {
                        if(g[i][j] == 1)
                            mark[idx ++] = j + 1;
                    }
                }
                ans.add(mark);
            }
            return;
        }
        //不放置皇后
        dfs(x,y + 1,s);
        // 放置皇后
        if(!row[x] && !col[y] && !dg[y + x] && !udg[y - x + n]){
            g[x][y] = 1;
            row[x] = true;
            col[y] = true;
            dg[x + y] = true;
            udg[y - x + n] = true;
            dfs(x,y + 1,s + 1);
            g[x][y] = 0;
            row[x] = false;
            col[y] = false;
            dg[x + y] = false;
            udg[y - x + n] = false;
        }
    }
    public static void main(String[] args){
        Scanner sc = new Scanner(new BufferedInputStream(System.in));
        n = sc.nextInt();
        dfs(0,0,0);
        Collections.sort(ans, new Comparator<int[]>() {
            @Override
            public int compare(int[] o1, int[] o2) {
                for(int i = 0;i < o1.length;i ++){
                    if(o1[i] != o2[i])
                        return o1[i] - o2[i];
                }
                return o1[0] - o2[0];
            }
        });
        for(int i = 0;i < 3;i ++){
            int[] res = ans.get(i);
            for(int j = 0;j < res.length;j ++)
                System.out.print(res[j] + " ");
            System.out.println();
        }
        System.out.println(ans.size());
    }
}