priority_queue

import { createQueue } from './queueu';

function createPriorityQueue() {
  const lowPriorityQueue = createQueue();
  const highPriorityQueue = createQueue();
  
  return {
    enqueue(item, isHighPriority = false) {
      isHighPriority
        ? highPriorityQueue.enqueue(item)
        : lowPriorityQueue.enqueue(item);
    },
    dequeue() {
      if(!highPriorityQueue.isEmpty()) {
        return highPriorityQueue.dequeue();
      }
      return lowPriorityQueue.dequeue();
    },
    peek() {
      if(!highPriorityQueue.isEmpty()) {
        return highPriorityQueue.peek();
      }
      return lowPriorityQueue.peek();
    },
    get length() {
      return highPriorityQueue.length +
        lowPriorityQueue.length;
    },
    isEmpty() {
      return highPriorityQueue.isEmpty() &&
        lowPriorityQueue.isEmpty();
    }
  }
}

const q = createPriorityQueue();
q.enqueue(1);
q.enqueue(2);
q.enqueue(3);

console.log(q.peek())
q.dequeue();
q.dequeue();
console.log(q.peek())
console.log(q.length)
q.enqueue(5, true);
console.log(q.peek())
console.log(q.length)
q.enqueue(6);
console.log(q.peek())
q.dequeue();
console.log(q.peek())