PHP算法：冒泡排序与快速排序

写一个排序算法，可以是冒泡排序或者快速排序，假设待排序对象是一个二维数组。（提示：不能使用系统已有函数，另外请仔细回忆以前学习过的基础知识）

1//冒泡排序<br>
2function bubble_sort($array)
{
&nbsp; &nbsp; <br>
3	$count = count($array);
&nbsp; &nbsp; <br>
4	if ($count <= 0) return false;

&nbsp; &nbsp; <br>
5	for($i=0; $i<$count; $i++){
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;<br>
6		for($j=$count-1; $j>$i; $j--){
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;<br>
7			if ($array[$j] < $array[$j-1]){
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; <br>
8				$tmp = $array[$j];
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; <br>
9				$array[$j] = $array[$j-1];
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp; <br>
10				$array[$j-1] = $tmp;
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;&nbsp; &nbsp;<br>
11			}
&nbsp; &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;<br>
12		}
&nbsp; &nbsp; <br>
13	}
&nbsp; &nbsp; <br>
14	return $array;
<br>
15}