@datastructures-js/heap/src/maxHeap.js

Min/Max Heap & Heap Sort implementation in javascript

/**
 * @license MIT
 * @copyright 2020 Eyas Ranjous <eyas.ranjous@gmail.com>
 */

const { Heap } = require('./heap');

const getMaxCompare = (getCompareValue) => (a, b) => {
  const aVal = typeof getCompareValue === 'function' ? getCompareValue(a) : a;
  const bVal = typeof getCompareValue === 'function' ? getCompareValue(b) : b;
  return aVal < bVal ? 1 : -1;
};

/**
 * @class MaxHeap
 * @extends Heap
 */
class MaxHeap extends Heap {
  /**
   * @param {function} [getCompareValue]
   * @param {array} [values]
   */
  constructor(getCompareValue, values) {
    super(getMaxCompare(getCompareValue), values);
    this._getCompareValue = getCompareValue;
  }

  /**
   * Inserts a new value into the heap
   * @public
   * @param {number|string|object} value
   * @returns {MaxHeap}
   */
  insert(value) {
    super.insert(value);
    return this;
  }

  /**
   * Inserts a new value into the heap
   * @public
   * @param {number|string|object} value
   * @returns {MaxHeap}
   */
  push(value) {
    return this.insert(value);
  }

  /**
   * Fixes node positions in the heap
   * @public
   * @returns {MaxHeap}
   */
  fix() {
    super.fix();
    return this;
  }

  /**
   * Returns a shallow copy of the MaxHeap
   * @public
   * @returns {MaxHeap}
   */
  clone() {
    return new MaxHeap(this._getCompareValue, this._nodes.slice());
  }

  /**
   * Builds a MaxHeap from an array
   * @public
   * @static
   * @param {array} values
   * @param {function} [getCompareValue]
   * @returns {MaxHeap}
   */
  static heapify(values, getCompareValue) {
    if (!Array.isArray(values)) {
      throw new Error('MaxHeap.heapify expects an array');
    }
    return new MaxHeap(getCompareValue, values);
  }

  /**
   * Checks if a list of values is a valid max heap
   * @public
   * @static
   * @param {array} values
   * @param {function} [getCompareValue]
   * @returns {boolean}
   */
  static isHeapified(values, getCompareValue) {
    return new MaxHeap(getCompareValue, values).isValid();
  }
}

exports.MaxHeap = MaxHeap;