LeetCode: Implement Queue using Stacks Solution

Implementation

1var MyQueue = function () {
2  this.s1 = []
3  this.s2 = []
4}
5
6MyQueue.prototype.push = function (x) {
7  while (this.s1.length) {
8    this.s2.push(this.s1.pop())
9  }
10  this.s1.push(x)
11  while (this.s2.length) {
12    this.s1.push(this.s2.pop())
13  }
14}
15
16MyQueue.prototype.pop = function () {
17  return this.s1.pop()
18}
19
20MyQueue.prototype.peek = function () {
21  return this.s1.slice(-1)[0]
22}
23
24MyQueue.prototype.empty = function () {
25  return !this.s1.length && !this.s2.length
26}

References

Original problem

Similar problems

Implement Stack using Queues