Nodejs Array Merge Sort mergeSort(arr)

Method Source Code

var mergeSort = function (arr) {
    var n = parseInt(arr.length/2);
    if(n < 1){
        return arr;
    }else{/*from   w w  w . ja v  a2  s.  c o m*/
        var arr1 = mergeSort(arr.slice(0, n));
        var arr2 = mergeSort(arr.slice(n));
    }
    var a = [];
    var i = 0, j = 0;
    while(i<arr1.length && j<arr2.length){
        if(arr1[i]<arr2[j]){
            a.push(arr1[i]);
            i++;
        }else{
            a.push(arr2[j]);
            j++;
        }
    }
    a = a.concat(arr1.slice(i));
    a = a.concat(arr2.slice(j));
    return a;
}

arr = [3,8,7,4,1,9,0,2,5,6];
var b = mergeSort(arr);
//arr.shellSort();
console.log(b);

Related

1. mergesort (arr, lo, hi)

   'use strict';
   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;
   ...
   

2. 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);
   

3. 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) {
   ...
   

4. 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
   ...