algs4js/dist/sorting/MergeSort.js

Basic algorithms and data structures implemented with es6

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

/**
 * Class MergeSort
 *
 * Implementation of the Quick Sort algorithm using the
 * Hoare partition algorithm.
 */
var MergeSort = function () {
  function MergeSort() {
    _classCallCheck(this, MergeSort);
  }

  _createClass(MergeSort, null, [{
    key: "sort",
    value: function sort(arr) {
      this.mergeSort(arr, 0, arr.length - 1);
    }
  }, {
    key: "mergeSort",
    value: function mergeSort(arr, left, right) {
      if (left >= right) {
        return;
      }
      var mid = Math.floor(left + (right - left) / 2);
      this.mergeSort(arr, left, mid);
      this.mergeSort(arr, mid + 1, right);
      this.merge(arr, left, mid, right);
      return;
    }

    /* eslint no-param-reassign: 0 */

  }, {
    key: "merge",
    value: function merge(arr, left, mid, right) {
      var arrCopy = arr.slice();
      var i = left;
      var j = mid + 1;
      var k = left;
      while (i <= mid && j <= right) {
        if (arrCopy[i] < arrCopy[j]) {
          arr[k] = arrCopy[i];
          i++;
        } else {
          arr[k] = arrCopy[j];
          j++;
        }
        k++;
      }
      while (i <= mid) {
        arr[k] = arrCopy[i];
        k++;
        i++;
      }
      while (j <= right) {
        arr[k] = arrCopy[j];
        k++;
        j++;
      }
    }
  }]);

  return MergeSort;
}();

exports.default = MergeSort;