<pre class="language-javascript"><code class="language-javascript">/* you can use this Class which is bundled together with your code

class Stack {
 push(element) { // add element to stack }
 peek() { // get the top element }
 pop() { // remove the top element}
 size() { // count of element }
}
*/

/* Array is disabled in your code */

// you need to complete the following Class
class Queue {
 constructor(){
 this.left = new Stack()
 this.right = new Stack()
 }
 enqueue(element) { 
 // add new element to the rare
 this.left.push(element)
 }
 peek() { 
 // get the head element
 // right size is zero then we need to push 
 // all the elements to right, which will be reversed hence peek will work
 
 if(this.right.size()==0){ // right size is zero then we need to push all the elements to right, which will be reversed hence peek will work
 while(this.left.size()){
 this.right.push(this.left.pop())
 }
 }
 // always return right, as it will always have a value
 return this.right.peek()
 }
 size() { 
 // return count of element
 // size is sum of left and right
 return this.left.size() + this.right.size()
 }
 dequeue() {
 // remove the head element
 if(this.right.size()==0){
 while(this.left.size()){
 this.right.push(this.left.pop())
 }
 }
 return this.right.pop()
 }
}


class Queue1 {
 stack = new Stack();
 enqueue(element) { 
 // add new element to the rare
 const reversed = new Stack();
 while(this.stack.size()){
 reversed.push(this.stack.pop());
 }
 reversed.push(element);
 while(reversed.size()){
 this.stack.push(reversed.pop());
 }
 }
 peek() { 
 // get the head element
 return this.stack.peek();
 }
 size() { 
 // return count of element
 return this.stack.size();
 }
 dequeue() {
 // remove the head element
 return this.stack.pop();
 }
}</code></pre>

Not Ideal but something interviewer will be looking for

In JavaScript, we could use array to work as both a Stack or a queue. const arr = [1, 2, 3, 4] arr.push(5) // now array is [1, 2, 3, 4, 5] arr.pop() /…

14. Implement a general memoization function - `memo()`

14. `memo()`を実装する

14. 实现`memo()`

12. implement Immutability helper

12. Immutability helperを実装する

12. 实现  Immutability helper

13. Implement a Queue by using Stack

13. Stackを使ってQueueを作る

13. 利用栈(Stack)创建队列(Queue)