Nodejs Array Merge Sort mergesort (arr, lo, hi)

Method Source Code

'use strict';/*from   w w  w. ja v  a 2s .com*/

Array.prototype.swap = function (i, j) {
  const temp = this[i];
  this[i] = this[j];
  this[j] = temp;
}

function mergesort (arr, lo, hi) {
  function partition (lo, hi) {
    if (lo >= hi) return;

    const mid = Math.floor((hi - lo) / 2) + lo;
    partition(lo, mid);
    partition(mid + 1, hi);
    merge(lo, mid, hi);
  }

  function merge (lo, mid, hi) {
    if (lo >= hi || arr[mid] <= arr[mid + 1]) return;

    const buf = arr.slice(lo, mid + 1), bufLen = buf.length;
    let leftIndex = 0, rightIndex = mid + 1;

    for (let i = lo; i <= hi; i++) {
      if      (leftIndex >= bufLen) arr[i] = arr[rightIndex++];
      else if (rightIndex > hi)     arr[i] = buf[leftIndex++];
      else                          arr[i] = arr[rightIndex] < buf[leftIndex] ? arr[rightIndex++] : buf[leftIndex++];
    }
  }

  partition(0, arr.length - 1);
  return arr;
}

const testArr = [5,2,78,5,0,13,6];
console.log(mergesort(testArr));

mergeSort(arr)

var mergeSort = function (arr) {
    var n = parseInt(arr.length/2);
    if(n < 1){
        return arr;
    }else{
        var arr1 = mergeSort(arr.slice(0, n));
        var arr2 = mergeSort(arr.slice(n));
    var a = [];
...

mergesort(A)

function merge(left, right) {
  var result = [];
  while(left.length > 0 || right.length > 0) {
    if(left.length > 0 && right.length > 0) {
      if(left[0] <= right[0]) {
        result.push(left.shift());
      } else {
        result.push(right.shift());
    } else if(left.length > 0) {
      result.push(left.shift());
    } else if(right.length > 0) {
      result.push(right.shift());
  return result;
function mergesort(A) {
  if(A.length < 2) {
    return A;
  var middle = Math.ceil(A.length / 2);
  var left = A.splice(0, middle);
  var right = A;
  left = mergesort(left);
  right = mergesort(right);
  return merge(left, right);
Array.prototype.mergeSort = function() {
  return mergesort(this);

mergesort(lst)

var arr = [2, 4, 6, 1, 3, 5, 8, 7];
var mergesort = function (lst) {
    if (lst.length === 1) return lst;
    var L = lst.slice(0, lst.length / 2),
        R = lst.slice(lst.length / 2, lst.length);
    var left = mergesort(L),
        right = mergesort(R);
    return merge(left, right);
    function merge(left, right) {
...

mergeSort(array)

function mergeSort(array) {
  var merge = function (left, right) {
    var total = []
    while (left.length && right.length)
      total.push(left[0] <= right[0] ? left.shift() : right.shift())
    return total.concat(left.concat(right));
  var length = array.length;
  if (length < 2) return array
...

mergeSort(array)

function merge(left, right) {
  const merged = [];
  while (left.length > 0 && right.length > 0) {
    let nextItem = (left[0] < right[0]) ? left.shift() : right.shift();
    merged.push(nextItem);
  return merged.concat(left, right);
function mergeSort(array) {
...

Nodejs Array Merge Sort mergesort (arr, lo, hi)

Method Source Code

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