php二分尋找

標籤：c   style   class   blog   code   java   

<?php/** * 二分尋找：尋找一個值在數組中的位置 *@$val：尋找的值 *@$arr：操作的數組，前提是按順序排列 */header("content-type:text/html;charset = utf-8");function biary_search($arr,$val){    $num = count($arr);    $low = 0;    $high = $num - 1;    while($low<$high){        $mid = floor(($high-$low)/2);        if ($arr[$mid] == $val){            return $mid;        }elseif ($arr[$mid]>$val){            $high = $mid -1;        }else {            $low = $mid+1;        }    }    return "not found";}$array = array(1,2,3,34,534,754,823,923);$index = biary_search($array, "34");echo $index;