priority-heap-queue

_Stability: 1 - Experimental_

Binary heap.

Installation

npm install priority-heap-queue

Tests

npm test

Usage

``javascript
var PriorityQueue = require('priority-heap-queue');

var maxQueue = new PriorityQueue();
var minQueue = new PriorityQueue({kind: 'min'});
`

Overview

_TODO_

Documentation

$3

A JavaScript implementation of a priority queue using heap data structure.

WARNING: This implementation uses 1-indexed arrays (instead of 0-indexed) arrays.

#### PriorityQueue.heapDecreaseKey(array, index, value)

* array: _Array_ 1-indexed array storing the heap structure
* index: _Integer_ index of the key to decrease
* value: _Integer_ the value to decrease the key to

Sets the value of the key at index to value and ensures heap property is maintained as a result.

#### PriorityQueue.heapIncreaseKey(array, index, value)

* array: _Array_ 1-indexed array storing the heap structure
* index: _Integer_ index of the key to increase
* value: _Integer_ the value to increase the key to

Sets the value of the key at index to value and ensures heap property is maintained as a result.

#### PriorityQueue.maxHeapify(array, index, heapSize)

* array: _Array_ 1-indexed array storing the heap structure
* index: _Integer_ the array index to start maxHeapify procedure on
* heapSize: _Integer_ heap size

Ensures that the max-heap property is satisfied for the sub-tree rooted at index of the array representing a binary tree.

#### PriorityQueeu.minHeapify(array, index, heapSize)

* array: _Array_ 1-indexed array storing the heap structure
* index: _Integer_ the array index to start maxHeapify procedure on
* heapSize: _Integer_ heap size

Ensures that the min-heap property is satisfied for the sub-tree rooted at index of the array representing a binary tree.

#### new PriorityQueue(options)

* options:
* kind: _String_ One of min, max (default: max)

Creates a new PriorityQueue.

#### priorityQueue.decreaseKey(index, value)

* index: _Integer_ index of the key to decrease
* value: _Integer_ the value to decrease the key to

Sets the value of the key at index to value and ensures heap property is maintained as a result.

#### priorityQueue.extractMax()

Removes and returns the element with the largest key.

#### priorityQueue.extractMin()

Removes and returns the element with the smallest key.

#### priorityQueue.increaseKey(index, value)

* index: _Integer_ index of the key to increase
* value: _Integer_ the value to increase the key to

Sets the value of the key at index to value and ensures heap property is maintained as a result.

#### priorityQueue.insert(key, element)

* key: _Integer_ key of the element to be inserted
* element: _Any_ element to associate with the key

Inserts the element into the priority queue at the specified key`.

#### priorityQueue.maximum()

Returns the element with the largest key. The element is _not_ removed.

#### priorityQueue.minimum()

Returns the element with the smallest key. The element is _not_ removed.