题解 | 栈和排序

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            in.nextLine();
            String[] s = in.nextLine().split(" ");
            Deque<String> deque = new ArrayDeque<>();
            Deque<String> res = new ArrayDeque<>();
            for(String c:s){
                deque.push(c);
                while(!deque.isEmpty() && deque.peek().equals(String.valueOf(n))){
                    res.push(deque.pop());
                    n--;
                }
            }

            while(!deque.isEmpty()){
                res.push(deque.pop());
            }

            //输出
            List<String> list = new ArrayList<>();
            while(!res.isEmpty()){
                list.add(res.pop());
            }
            Collections.reverse(list);
            for(String a :list){
                System.out.print(a+" ");
            }
            
        }
    }
}