题解 | #用递归函数和栈逆序一个栈#

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

public class CD7_用递归函数和栈逆序一个栈
{
    //  递归函数一：将栈底的元素返回并移除
    public static int getAndRemoveLastElement(Stack<Integer> stack)
    {
        // 记录位置方便递归
        int x = stack.pop();
        if (stack.isEmpty())
        {
            return x;
        }
        else
        {
            int last = getAndRemoveLastElement(stack);
            stack.push(x); // 恢复原来顺序
            return last;
        }
    }
    public static void reverse(Stack<Integer> stack)
    {
        if (stack.isEmpty())
        {
            return ;
        }
        int x = getAndRemoveLastElement(stack);
        reverse(stack);
        stack.push(x);
    }


    public static void main(String[] args)
    {
        Stack<Integer> stack = new Stack<>();
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());
        for (int i = 1; i <= n; i++)
        {
            int x = scanner.nextInt();
            stack.push(x);
        }
        reverse(stack);
        while (!stack.isEmpty())
        {
            System.out.print(stack.pop() + " ");
        }
        System.out.println();
    }
}