PHP 빠른 정렬

<?php
//Quick Sort
function quickSort(array $array){
  static $run = 0;  
  $len = count($array);
  if($len <= 1) return $array;
  $arrleft=array();
  $arrright=array();
  $flag = $array[0];
  for($i=1;$i<$len;$i++){
 if($array[$i]<=$flag){
$arrleft[]=$array[$i];
 }else{
$arrright[] = $array[$i];
 }
  }
   $arrleft = quickSort($arrleft);
   $arrright = quickSort($arrright);
  $run++;
  return array_merge($arrleft,array($flag),$arrright);
}
$data= array(10,12,43,32,123,12);
$newarr = quickSort($data);
print_r($newarr);
?>