heap

Heap

A heap is a specialized tree-based data structure which is essentially an almost complete tree that satisfies the heap property :in a max heap, for any given node C, if P is a parent node of C, then the key (the value) of P is greater than or equal to the key of C. In a min heap, the key of P is less than or equal to the key of C. The node at the "top" of the heap (with no parents) is called the root node.

Installation

Install with npm

npm i javascript-algo-ds

Import in your javascript file as:

const Heap = require('javascript-algo-ds/src/data-structure/heap/heap')
const MinHeap = require('javascript-algo-ds/src/data-structure/heap/minHeap')
const MaxHeap = require('javascript-algo-ds/src/data-structure/heap/maxHeap')

API

Constructor

Syntax

const minHeap = new MinHeap(compareFunc)
const maxHeap = new MaxHeap(compareFunc)

Parameters

• compareFunction - function
  • Default value - undefined

Properties

• heap - array of objects in ordered way
• size - number of elements in the heap
• compare - comparator of type Comparator

Methods

• heap.isEmpty()
• heap.add(item)
• heap.peek()
• heap.poll()
• heap.remove(item)
• heap.find(item)
• heap.toString()

Static methods

• fromArray()

heap.isEmpty()

Checks if the heap contains at least one element or not.

Returns

Returns boolean

heap.add(item)

Adds item to the heap followed by heapifying.

Parameters

• item - T
  • The value to be added.

Returns

Returns this

heap.peek()

Returns the element at root of the heap.

Returns

Type - T | null

heap.poll()

Remove and returns the element at root of the heap followed by heapifying.

Returns

Type - T | null

heap.remove(item)

Parameters

• item - T
  • The item to be removed. Remove the element matching item using custom compare function (if passed) at root of the heap followed by heapifying.

Returns

Type - this

heap.find(item)

Finds the element matching item using custom compare function (if passed) and returns their indices in heap.heap array.

Parameters

• item - T
  • The item to be found.

Returns

Type - number[]

heap.toString()

Converts the heap in array and returns it

Returns

Type - String

Heap.fromArray()

@static
Creates the heap from an array

Parameters

• array - T[]
  • Array of objects
• compareFunction - function
  • Default value - undefined

Returns

Type - MinHeap | MaxHeap | Heap