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139 root 1 <?php
2 // +----------------------------------------------------------------------+
3 // | PHP Version 4 |
4 // +----------------------------------------------------------------------+
5 // | Copyright (c) 1997-2004 The PHP Group |
6 // +----------------------------------------------------------------------+
7 // | This source file is subject to version 3.0 of the PHP license, |
8 // | that is bundled with this package in the file LICENSE, and is |
9 // | available at through the world-wide-web at |
10 // | http://www.php.net/license/3_0.txt. |
11 // | If you did not receive a copy of the PHP license and are unable to |
12 // | obtain it through the world-wide-web, please send a note to |
13 // | license@php.net so we can mail you a copy immediately. |
14 // +----------------------------------------------------------------------+
15 // | Authors: Aidan Lister <aidan@php.net> |
16 // +----------------------------------------------------------------------+
17 //
18 // $Id: bcpowmod.php,v 1.2 2005/11/22 20:24:45 aidan Exp $
19  
20  
21 /**
22 * Replace bcpowmod()
23 *
24 * @category PHP
25 * @package PHP_Compat
26 * @link http://php.net/function.bcpowmod
27 * @author Sara Golemon <pollita@php.net>
28 * @version $Revision: 1.2 $
29 * @since PHP 5.0.0
30 * @require PHP 4.0.0 (user_error)
31 */
32 if (!function_exists('bcpowmod')) {
33 function bcpowmod($x, $y, $modulus, $scale)
34 {
35 // Sanity check
36 if (!is_scalar($x)) {
37 user_error('bcpowmod() expects parameter 1 to be string, ' .
38 gettype($x) . ' given', E_USER_WARNING);
39 return false;
40 }
41  
42 if (!is_scalar($y)) {
43 user_error('bcpowmod() expects parameter 2 to be string, ' .
44 gettype($y) . ' given', E_USER_WARNING);
45 return false;
46 }
47  
48 if (!is_scalar($modulus)) {
49 user_error('bcpowmod() expects parameter 3 to be string, ' .
50 gettype($modulus) . ' given', E_USER_WARNING);
51 return false;
52 }
53  
54 if (!is_scalar($scale)) {
55 user_error('bcpowmod() expects parameter 4 to be integer, ' .
56 gettype($scale) . ' given', E_USER_WARNING);
57 return false;
58 }
59  
60 $t = '1';
61 while (bccomp($y, '0')) {
62 if (bccomp(bcmod($y, '2'), '0')) {
63 $t = bcmod(bcmul($t, $x), $modulus);
64 $y = bcsub($y, '1');
65 }
66  
67 $x = bcmod(bcmul($x, $x), $modulus);
68 $y = bcdiv($y, '2');
69 }
70  
71 return $t;
72 }
73 }
74  
130 kaklik 75 ?>