python二分查询:

import math

#二分查询(使用有序列表)

def binary_sear(list, item):

    low = 0

    high = len(list) - 1

    while (low <= high):

        mid = math.ceil((low + high) / 2)

        search = list[mid]

        if (search == item):

            return mid

        elif (search > item):

            high = mid - 1;

        else:

            low = mid + 1;

    return None;

lists = [1,2,3,4,5,6,7]

print(binary_sear(lists, 4))

php二分查询:

function binary_sear($arr, $val)

{

    $low = 0;

    $high = count($arr) - 1;

    while($low <= $high) {

        $mid = ceil(($high+$low)/2);

        $search = $arr[$mid];

        if ($search == $val) {

            return $mid;

        } elseif ($search > $val) {

            $high = $mid - 1;

        } else {

            $low = $mid + 1;

        }

    }

}

$arr = [1,2,3,4,5,6,7];

var_dump(binary_sear($arr, 4));

php和python的写法 方便不会python的童鞋看