暴力递归-逆序栈

题目：给你一个栈，请你逆序这个栈 

package Algorithms.ViolenceRecursive;

import java.util.Stack;

public class ReverseStackUsingRecursive {

    //逆序栈
    public static void reverse(Stack<Integer> stack) {
        if (stack.isEmpty()) {
            return;
        }
        int i = getAndRemoveLastElement(stack);
        reverse(stack);
        stack.push(i);
    }

    //移除栈底元素并返回
    public static int getAndRemoveLastElement(Stack<Integer> stack) {
        int result = stack.pop();
        if (stack.isEmpty()) {
            return result;
        } else {
            int last = getAndRemoveLastElement(stack);
            stack.push(result);
            return last;
        }
    }

    public static void main(String[] args) {
        Stack<Integer> test = new Stack<Integer>();
        test.push(1);
        test.push(2);
        test.push(3);
        test.push(4);
        test.push(5);
        reverse(test);
        while (!test.isEmpty()) {
            System.out.println(test.pop());
        }

    }

}

过程解析：

    public static int getAndRemoveLastElement(Stack<Integer> stack) { // 1 2 3
        int result = stack.pop(); //(1)弹1
        if (stack.isEmpty()) {
            return result;
        } else {
            int last = getAndRemoveLastElement(stack);
            {
                int result = stack.pop(); //(2) 弹2
                if (stack.isEmpty()) {
                    return result;
                } else {
                    int last = getAndRemoveLastElement(stack);
                    {
                        int result = stack.pop(); //(3) 弹3
                        if (stack.isEmpty()) { 
                            return result; //(4)返回3
                        } else {
                            int last = getAndRemoveLastElement(stack);
                            stack.push(result);
                            return last;
                        }
                    }
                    stack.push(result); //(5) 压2
                    return last; //(6) 返回3
                }
            }
            stack.push(result);  //(7)压1
            return last; (8)//返回3
        }
    }

 逆序栈：

    public static void reverse(Stack<Integer> stack) { //1 2 3
        if (stack.isEmpty()) {
            return;
        }
        int i = getAndRemoveLastElement(stack); // (1)i = 3  栈中剩余：1 2
        reverse(stack);
        {
            if (stack.isEmpty()) {
                return;
            }
            int i = getAndRemoveLastElement(stack); //(2)i = 2  栈中剩余：1 
            reverse(stack);
            {
                if (stack.isEmpty()) {
                    return;
                }
                int i = getAndRemoveLastElement(stack);//(3) i = 1  栈空
                reverse(stack); // (4)栈空，递归结束
                stack.push(i); //(5)压1
            }
            stack.push(i); //(6)压2
        }
        stack.push(i); //(7)压3
    }