Insertion Sort

 1 <?php

 2 function swap(&$a, &$b){

 3     $c = $a;

 4     $a = $b;

 5     $b = $c;

 6 }

 7 

 8 # insertion sort

 9 # ascend

10 function sortInsertion(&$a){ # a is an array of numbers

11 

12     # length of a

13     $m = count($a);

14 

15     if($m < 2){

16         return;

17     }

18 

19     # for m numbers, we have m-1 numbers to insert

20     for($i=1; $i<=$m-1; $i++){

21         for($j=$i; $j>0; $j--){

22             if($a[$j] < $a[$j-1]){

23                 swap($a[$j], $a[$j-1]);

24             }

25         }

26     }

27 

28     return;

29 }

30 

31 $arr = range(5, 0);

32 sortInsertion($arr);

33 echo implode(', ', $arr);

34 

35 // 0, 1, 2, 3, 4, 5

36 ?>