Queue from Stack

Directions

Implement a Queue datastructure using two stacks.
*Do not* create an array inside of the 'Queue' class.
Queue should implement the methods 'add', 'remove', and 'peek'.
For a reminder on what each method does, look back
at the Queue exercise.

Examples:

const q = new Queue();
q.add(1);
q.add(2);
q.peek(); // returns 1
q.remove(); // returns 1
q.remove(); // returns 2

Solutions

• Solution #2

    const Stack = require('./stack');
  
    class Queue {
      constructor() {
        this.stackOne = new Stack();
        this.stackTwo = new Stack();
      }
    
      add(el) {
        while (this.stackOne.peek()) {
          this.stackTwo.push(this.stackOne.pop());
        }
        
        this.stackOne.push(el);
    
        while (this.stackTwo.peek()) {
          this.stackOne.push(this.stackTwo.pop());
        }
    
      }
    
      remove() {
        return this.stackOne.pop();
      }
    
      peek() {
        return this.stackOne.peek();
      }
    }