Recursive PHP Insertion Sort

sort.php

<?php

function insertion_sort($a, $n, $i){
    if($i == $n-1){
        // Nothing to do since we're looking at the last element. Just return
        // the array as-is.
        return $a;
    }
    else{
        $sorted = insertion_sort($a, $n, $i+1);
        $el = $a[$i];

        // All elements to the right of index $i are assumed to be sorted.
        // Now we just have to figure out where $el fits in the sorted array
        for($j = $i+1; $j<$n; $j++){
            if($el > $sorted[$j]){
                // $el is bigger, swap so $el moves to the right in the array.
                $sorted[$j-1] = $sorted[$j];
                $sorted[$j] = $el;
            }
        }
        return $sorted;
    }
}

$arr = array(2,8,9,0,0,2,3);

$sorted_arr = insertion_sort($arr, count($arr), 0);

echo '<pre>';
print_r($sorted_arr);
echo '</pre>';

?>