<?php

/**

 * Created by PhpStorm.

 * User: Administrator

 * Date: 16-8-29

 * Time: ����3:02

 *

 * ��������

 *

 */

function quick_sort($arr){

    $length = count($arr);

    if($length<=1){

        return $arr;

    }

    $base_num=$arr[0];

    $left_array=array();

    $right_array=array();

    for($i=1; $i<$length; $i++){

        if($base_num>$arr[$i])

            $left_array[]=$arr[$i];

        else

            $right_array[]=$arr[$i];

    }

    $left_array=quick_sort($left_array);

    $right_array=quick_sort($right_array);

    return array_merge($left_array, array($base_num), $right_array);

}

$arr=array(23,50,60,31,68,90,15,18,51,10);

$arr=quick_sort($arr);

var_dump($arr);