php非递归二分查找 

 1 <?php
 2 function check_data($array,$key){
 3     $start = 0;//开始数组下标
 4     $end = count($array)-1;//结束数组下标
 5     $c = 0;//循环次数
 6     while($start <= $end ){
 7         $c++;
 8         $mid = floor(($start+$end)/2);//数组中间下标
 9         if($key > $array[$mid]){
10             $start = $mid;
11             if($end - $start == 1){
12                 $check = 'not exist';
13                 break;
14             }
15         }elseif($key < $array[$mid]){
16             $end =  $mid;
17             if($end - $start == 1){
18                 $check = 'not exist';
19                 break;
20             }
21         }elseif($key == $array[$mid]){
22             $check = $key;
23             break;    
24         }
25     }
26     return array($check,$c);
27 }
28 print_r(check_data(array(1,2,3,4,5,7,9,12,16,23,45,46,49,50,56),'51'));
29 ?>
posted @ 2012-03-20 12:16  小冰PHPer  阅读(203)  评论(0)    收藏  举报