StackQueue.md

JavaScript

function Queue() {
  this.pushS = new Stack();
  this.popS = new Stack();
}

Queue.prototype.enqueue = function(val) {
  this.pushS.push(val);
};

Queue.prototype.dequeue = function() {
  var popping = this.popS;
  var pushing = this.pushS;

  if (popping.peek()) {
    var deq = popping.pop();
    console.log("Dequeuing " + deq + " from stack.");
    return deq;
  }

  while (pushing.top) {
    popping.push(pushing.pop());
  }
};

------ ANOTHER SOLUTION ----------

class Queue { constructor() { this.in = new Stack(); this.out = new Stack(); }

enqueue(val) { this.in.push(val) }

dequeue() { this.move(); return this.out.pop(); }

move() { if(this.out.isEmpty()) { while(!this.in.isEmpty()) { this.out.push(this.in.pop()) } } }

isEmpty() { return this.in.isEmpty() && this.out.isEmpty(); }

peek() { this.move(); return this.out.peek(); } }