@datastructures-js/priority-queue

@datastructures-js/priority-queue

A highly performant priority queue implementation using a Min Heap data structure.

Table of Contents

• Install
• API
  • require
  • import
  • creating a priority queue
  • .enqueue(element, priority)
  • .front()
  • .back()
  • .dequeue()
  • .isEmpty()
  • .size()
  • .toArray()
  • .clear()
• Build
• License

Install

npm install --save @datastructures-js/priority-queue

API

require

const PriorityQueue = require('@datastructures-js/priority-queue');

import

import PriorityQueue from '@datastructures-js/priority-queue';

Create a Priority Queue

const priorityQueue = new PriorityQueue();

.enqueue(element, priority)

adds an element with a priority (number) to the queue. The smaller the number, the higher the priority.

runtime	params
O(log(n))	element: object priority: number

priorityQueue.enqueue('patient y', 1); // highest priority
priorityQueue.enqueue('patient z', 3);
priorityQueue.enqueue('patient w', 4); // lowest priority
priorityQueue.enqueue('patient x', 2);

.front()

returns the element with highest priority in the queue.

runtime	return
O(1)	object

console.log(priorityQueue.front()); // patient y

.back()

returns an element with lowest priority in the queue. If multiple elements exist at the lowest priority, the one that was inserted first will be returned.

runtime	return
O(1)	object

priorityQueue.enqueue('patient m', 4); // lowest priority
priorityQueue.enqueue('patient c', 4); // lowest priority
console.log(priorityQueue.back()); // patient w

.dequeue()

removes and returns the element with highest priority in the queue.

runtime	return
O(log(n))	object

console.log(priorityQueue.dequeue()); // patient y
console.log(priorityQueue.front()); // patient x

.isEmpty()

checks if the queue is empty.

runtime	return
O(1)	{boolean}

console.log(priorityQueue.isEmpty()); // false

.size()

returns the number of elements in the queue.

runtime	return
O(1)	number

console.log(priorityQueue.size()); // 5

.toArray()

returns an sorted array of elements from highest priority to lowest.

runtime	return
O(n*log(n))	array

console.log(priorityQueue.toArray()); // ['patient x', 'patient z', 'patient c', 'patient w', 'patient m']

.clear()

clears all elements in the queue.

runtime
O(1)

priorityQueue.clear();
console.log(priorityQueue.size()); // 0
console.log(priorityQueue.front()); // null
console.log(priorityQueue.dequeue()); // null

Build

grunt build

License

The MIT License. Full License is here