Parsing the php binary method to find whether an array contains a certain element _ PHP Tutorial

Source: Internet
Author: User
Parse the php binary method to check whether an array contains a certain element. The binary search array contains a certain element and is compatible with positive and negative order. code implementation: Copy the code as follows :? Php $ searchValue (int) $ _ GET [key]; functionsearch (array $ array, $ va binary lookup array contains a certain element, compatible with positive and negative order, code implementation:

The code is as follows:



$ SearchValue = (int) $ _ GET ['key'];

Function search (array $ array, $ value)
{
$ Max = count ($ array)-1;
$ Min = 0;
$ IsAscSort = $ array [$ min] <$ array [$ max];

While (TRUE ){
$ Sum = $ min + $ max;
$ MidKey = (int) ($ sum % 2 = 1? Ceil ($ sum/2): $ sum/2 );

If ($ max <$ min ){
Return-1;
} Else if ($ value = $ array [$ midKey]) {
Return 1;
} Else if ($ value> $ array [$ midKey]) {
$ IsAscSort? $ Min = $ midKey + 1: $ max = $ midKey-1;
} Else if ($ value <$ array [$ midKey]) {
$ IsAscSort? $ Max = $ midKey-1: $ min = $ midKey + 1;
}
}
}

$ Array = array (
'4', '5', '7', '8', '9', '10', '11', '12'
);
// Forward
Echo search ($ array, $ searchValue );

// Reverse order
Rsort ($ array );
Echo search ($ array, $ searchValue );


I have searched for this before and have read the Baidu encyclopedia example (Java implementation). There are some other Code written by other technical experts, which is problematic and cannot be implemented at all, these people are misleading when they are not tested. you can search for them and share them with others if you have nothing to worry about yesterday.
This does not take into account the unordered key array, mainly the method. if you need it, you can expand it on your own.

The pipeline code is as follows :? Php $ searchValue = (int) $ _ GET ['key']; function search (array $ array, $ va...

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