Insert sort _Python with PHP implementation version of recommended

Insert sort Python implementation

import random

a=[random.randint(1,999) for x in range(0,36)]

#  Direct insertion sort algorithm 
def insertionSort(a):
  for i in range(1,len(a)):
    #  If the subscript for i Is less than the subscript is i-1 , then subscript is i Put the elements in the right place 
    if a[i] < a[i-1]:
      tmp = a[i]
      j = i-1
      #  Looking for a[i] The appropriate location and will a[i-1] to a[i] The elements of the new position move back in order 
      while j >= 0 and tmp < a[j]:
        a[j+1] = a[j]
        j = j-1

      #  will a[i] Put it in a new position 
      a[j+1] = tmp

insertionSort(a)
print(a)

Insertion sort PHP implementation

<?php
//  Generate an array to sort 
$a = [];
for($i=0;$i<36;$i++){
  array_push($a,mt_rand(1,999));
}
shuffle($a);

/**
 *  Insertion sort  insertion sort
 * @param [type] $a  A reference to an array to be sorted 
 * @return null
 */
function insertionSort(&$a){
  for($i = 1;$i<count($a);$i++){
    //  If the subscript for i Is less than the subscript is i-1 , then subscript is i Put the elements in the right place 
    if($a[$i] < $a[$i-1]){
      $tmp = $a[$i];
      //  Looking for a[i] The appropriate location and will a[i-1] to a[i] The elements of the new position move back in order 
      for($j = $i-1; $j>=0 && $tmp<$a[$j];$j--)
        $a[$j+1] = $a[$j];
      //  will a[i] Put it in a new position 
      $a[$j+1] = $tmp;
    }
  }

}

insertionSort($a);
var_dump($a);

Insertion sort time complexity analysis

The insertion sort algorithm has a time complexity of O (n2), but the insertion sort performs better than bubbling and selection sort.