<?
php
/**
* 二分查找：查找一个值在数组中的位置
*@$val：查找的值
*@$arr：操作的数组，前提是按顺序排列
*/
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;
转载于:https://www.cnblogs.com/eterwei/p/3774956.html
