232-implement-queue-using-stacks.js

//11/20/2020 Friday

// Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

// push(x) -- Push element x onto stack.
// pop() -- Removes the element on top of the stack.
// top() -- Get the top element.
// getMin() -- Retrieve the minimum element in the stack.


/**
 * Initialize your data structure here.
 */
var MyQueue = function() {
 this.stack = [];
 this.temp = [];
 };
 
// /**
// * Push element x to the back of queue. 
// * @param {number} x
// * @return {void}
// */
 MyQueue.prototype.push = function(x) { //2
 
 while(this.stack.length !== 0){
 this.temp.push(this.stack.pop())
 console.log("::::1 ", this.stack)
 }
 this.stack.push(x) 
 
 while(this.temp.length !== 0){
 this.stack.push(this.temp.pop())
 console.log("::::2 ", this.stack)
 }
 console.log(":::::::3", this.stack)
 };
 
// /**
// * Removes the element from in front of queue and returns that element.
// * @return {number}
// */
 MyQueue.prototype.pop = function() {
 return this.stack.pop() 
 
 };
 
// /**
// * Get the front element.
// * @return {number}
// */
 MyQueue.prototype.peek = function() {
 return this.stack[this.stack.length-1] //only show the first element of the queue
 };
 
// /**
// * Returns whether the queue is empty.
// * @return {boolean}
// */
 MyQueue.prototype.empty = function() {
 // return this.stack.isEmpty()
 if(this.stack.length === 0 || this.stack[0] === "empty"){
 
 return true
 }else {
 return false
 }
 };
 
 /** 
 * Your MyQueue object will be instantiated and called as such:
 * var obj = new MyQueue()
 * obj.push(x)
 * var param_2 = obj.pop()
 * var param_3 = obj.peek()
 * var param_4 = obj.empty()
 */