1 <?php
2 //快速排序
3 function partition(&$arr, $low, $high)
4 {
5 $pivotkey = $arr[$low];
6 while ($low < $high) {
7 while ($low < $high && $arr[$high] >= $pivotkey) {
8 $high--;
9 }
10 $temp = $arr[$low];
11 $arr[$low] = $arr[$high];
12 $arr[$high] = $temp;
13 while ($low < $high && $arr[$low] <= $pivotkey) {
14 $low++;
15 }
16 $temp = $arr[$low];
17 $arr[$low] = $arr[$high];
18 $arr[$high] = $temp;
19 }
20 return $low;
21 }
22
23 /**
24 * @param $arr 数组
25 * @param $low 数据排序 起始位置(下标)
26 * @param $high 数据排序 结束位置(下标)
27 */
28 function quick_sort(&$arr, $low, $high)
29 {
30 if ($low < $high) {
31 $pivot = partition($arr, $low, $high);
32 quick_sort($arr, $low, $pivot - 1);
33 quick_sort($arr, $pivot + 1, $high);
34 }
35 }
36
37 $arr = array(10,9,8,7,6,5);
38 quick_sort($arr, 3,4);
39 echo '<pre>';
40 foreach ($arr as $v) {
41 echo $v.'<br/>';
42 }