Using stack to realize queue out and in

*  Realize the idea ：
*
*  1） Prepare two stacks stack1 and stack2
*  2） When in line , Data first to stack1 in push
*  3） When out of queue , First judge stack2 Is it empty ,
*      3.1） If it is empty, it will stack1 The elements in the are in turn stack2 in push（ until stack1 It's empty ）, And then from stack2 A pop-up element returns 
*      3.2） If it's not empty , explain stack1 All the data in has been transferred to stack2, Directly from stack2 Back in .
*       Subsequent inserts are inserted directly into stack1 in , When stack2 After the element in is empty , then stack1 Put all the elements in stack2 in . And so on , Realization FIFO effect 
*

On rehuhu Code for ！！

package com.lll.algorithms.collection.queue;

import java.util.Stack;

/**
 * @ClassName : MyQueueWithStack
 * @Description:  Use the stack to realize the queue out and in 
 * @Author: liulianglin
 * @Date: 2021/10/14 15:17
 * @Version : 1.0
 *
 *  Realize the idea ：
 *
 *  1） Prepare two stacks stack1 and stack2
 *  2） When in line , Data first to stack1 in push
 *  3） When out of queue , First judge stack2 Is it empty ,
 *      3.1） If it is empty, it will stack1 The elements in the are in turn stack2 in push（ until stack1 It's empty ）, And then from stack2 A pop-up element returns 
 *      3.2） If it's not empty , explain stack1 All the data in has been transferred to stack2, Directly from stack2 Back in .
 *       Subsequent inserts are inserted directly into stack1 in , When stack2 After the element in is empty , then stack1 Put all the elements in stack2 in . And so on , Realization FIFO effect 
 *
 */
public class MyQueueWithStack<T> {
    private Stack<T> stack1 = new Stack<>();
    private Stack<T> stack2 = new Stack<>();

    public boolean mpush(T t){
        return stack1.push(t)==null ? false:true;
    }

    public T mpop(){
        if (stack2.empty()){
            while(!stack1.empty()){
                stack2.push(stack1.pop());
            }
        }
        return stack2.pop();
    }


    public static void main(String[] args) {
        MyQueueWithStack<Integer> myQueueWithStack = new MyQueueWithStack<>();
        myQueueWithStack.mpush(1);
        myQueueWithStack.mpush(3);
        myQueueWithStack.mpush(9);

        System.out.println(myQueueWithStack.mpop());
        System.out.println(myQueueWithStack.mpop());
        System.out.println(myQueueWithStack.mpop());
    }
}