PHP的排序算法跟查找算法

 1 $arr = array(15,8,20,50,37,85,10,5,11,4);
 2   //冒泡排序
 3   function maoPao($arr){
 4     for($i = 0; $i < count($arr)-1; $i++){
 5         for($j = 0; $j < count($arr)-1; $j++){
 6             if($arr[$j] > $arr[$j+1]){
 7                 $temp = $arr[$j];
 8                 $arr[$j] = $arr[$j+1];
 9                 $arr[$j+1] = $temp;
10             }
11         }
12     }
13     return $arr;
14   }

 1 $arr = array(15,8,20,50,37,85,10,5,11,4);
 2   //快速排序
 3   function fastSort($arr){
 4     $len = count($arr);
 5     
 6     if($len <= 1){
 7         return $arr;
 8     }
 9     
10     $key = $arr[0];
11     $left = array();
12     $right = array();
13     
14     for($i = 1; $i < $len; $i++){
15         if($arr[$i] > $key){
16             $right[] = $arr[$i];
17         } else {
18             $left[] = $arr[$i];
19         }
20     }
21     
22     $left = fastSort($left);
23     $right = fastSort($right);
24     
25     return array_merge($left, array($key), $right);
26   }

1 function search($arr, $val){
2     foreach($arr as $k => $v){
3         if($v == $val){
4             return $k;
5         }
6     }
7     return -1;
8 }

 1 //二分查找法
 2   function binSearch($arr, $val){
 3     $len = count($arr);
 4     $low = 0;
 5     $end = $len - 1;
 6     
 7     while($low <= $end){
 8         $mid = floor(($low+$end)/2);
 9         
10         if($arr[$mid] == $val){
11             return $mid;
12         } else if($arr[$mid] > $val){
13             $end = $mid - 1;
14         } else {
15             $low = $mid + 1;
16         }
17     }
18     
19     return -1;
20   }