[php] 数据结构&算法(PHP描述) 快速排序 quick sort 

 1 <?php
 2 /**
 3  * 快速排序 quick sort
 4  * 
 5  **/
 6 
 7 function sort_quick($arrData) {
 8     if(empty($arrData) || !is_array($arrData)) return false;
 9 
10     $flag = $arrData[0];
11     $len  = count($arrData) - 1;
12     if($len == 0) return $arrData; // 如果只有一个数据的数组直接返回
13 
14     $arrLeft  = array();
15     $arrRight = array();
16     $len_l    = 0;
17     $len_r    = 0;
18     for($i = 1; $i <= $len;$i++) {
19         if($arrData[$i] < $flag) {
20             $arrLeft[$len_l]  = $arrData[$i]; // 小于的放左边
21             $len_l++;
22         } else {
23             $arrRight[$len_r] = $arrData[$i]; // 大于等于的放右边
24             $len_r++;
25         } 
26     }
27 
28     // 合并数组
29     $arrResult = array();
30     if($len_l) {
31         $arrLeft = sort_quick($arrLeft);
32         for($i = 0;$i <= $len_l - 1; $i++ ) {
33             $arrResult[$i] = $arrLeft[$i]; 
34         }
35     }
36     $arrResult[$len_l] = $flag;
37     $len_l++;
38     if($len_r) {
39         $arrRight = sort_quick($arrRight);
40         for($i = 0;$i <= $len_r - 1; $i++ ) {
41             $arrResult[$len_l] = $arrRight[$i];
42             $len_l++;
43         }
44     }
45     echo "== ",$flag," ==========================================<br/>";
46     echo "data        : ",print_r($arrData),"<br/>";
47     echo "filter  left: ",print_r($arrLeft),"<br/>";
48     echo "filter right: ",print_r($arrRight),"<br/>"; 
49     echo "return      : ",print_r($arrResult),"<br/>"; 
50 
51     return $arrResult;
52 }
53 //$list = array(4,3,2,1,5,7,3,7);
54 $list = array(4,51,6,73,2,5,9,33,50,3,4,6,1,4,67);
55 $list = sort_quick($list);
56 echo "<pre>";print_r($list);

posted on 2012-06-20 14:32  bluefrog  阅读(1108)  评论(3)  编辑  收藏  举报