题解 | 栈和排序

import java.util.Scanner;
import java.util.Stack;

/**
 * @author supermejane
 * @date 2025/10/1
 * @description
 */
public class Main {

    private static Stack<Integer> stack = new Stack<>();

    // 注意类名必须为 Main, 不要有任何 package xxx 信息
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int[] a = new int[1000000];
        // 注意 hasNext 和 hasNextLine 的区别
        int cnt = in.nextInt();

        for (int i = 0; i < cnt; i++) {
            a[i] = in.nextInt();
        }
        int max = Integer.MIN_VALUE;
        int[] maxArr = new int[cnt];
        for (int i = cnt - 1; i >= 0; i--) {
            if (a[i] > max) max = a[i];
            maxArr[i] = max;
        }

        boolean flag = false;
        for (int i = 0; i < cnt; i++) {
            if (a[i] < maxArr[i]) stack.push(a[i]);
            else {
                if (!flag) {
                    System.out.print(a[i]);
                    flag = true;
                } else {
                    System.out.print(" " + a[i]);
                }
            }
        }
        while (!stack.isEmpty()) {
            if (!flag) {
                System.out.print(stack.pop());
                flag = true;
            } else {
                System.out.print(" " + stack.pop());
            }
        }
    }

}