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bcmod — Modulo zweier Zahlen mit beliebiger Genauigkeit
Liefert den Modulo des left_operand unter Verwendung von modulus.
Der linke Operand in Stringform.
Der Modulo-Wert in Stringform.
Gibt den Modulo als String zurück. Ist modulus 0, wird NULL zurückgegeben.
Beispiel #1 bcmod()-Beispiel
<?php
echo bcmod('4', '2'); // 0
echo bcmod('2', '4'); // 2
?>
GCD made in Euclidian algorithm:
<?php
function bcgcd($a, $b)
{
if($a < $b)
{
$t = $b;
$b = $a;
$a = $t;
unset($t);
}
if(bcmod($a, $b) == "0") return $b;
else return bcgcd($b, bcmod($a, $b));
}
?>
hope this helps.
Heres an useful IBAN generate function:
<?php
function controleer_iban($iban) {
$iban = str_replace(array(" ", " ", " ", "\t"), "", $iban);
$iban = strtoupper(str_replace(" ", "", $iban));
if(strlen($iban)>34)
return false;
$acceptabel = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1 2 3 4 5 6 7 8 9 0";
$acceptabel = explode(" ", $acceptabel);
for($i = 0; $i<strlen($iban); $i++) {
if(in_array(substr($iban, $i, 1), $acceptabel) === false)
return false;
}
$alfa = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z";
$alfa = explode(" ", $alfa);
for($i = 1; $i<27; $i++) {
$alfa_replace[] = $i+9;
}
$controlegetal = str_replace($alfa, $alfa_replace, substr($iban, 4, strlen($iban)-4).substr($iban, 0, 2)."00");
$controlegetal = 98 - (int)bcmod($controlegetal,97);
if((int)$controlegetal === (int)substr($iban, 2, 2))
return true;
else
return false;
}
?>
function bc_is_even($int_str) {
return (int)!($int_str & 1);
}
More resource efficient version of 'bc_is_even'.
<?php
/**
* my_bcmod - get modulus (substitute for bcmod)
* string my_bcmod ( string left_operand, int modulus )
* left_operand can be really big, but be carefull with modulus :(
* by Andrius Baranauskas and Laurynas Butkus :) Vilnius, Lithuania
**/
function my_bcmod( $x, $y )
{
// how many numbers to take at once? carefull not to exceed (int)
$take = 5;
$mod = '';
do
{
$a = (int)$mod.substr( $x, 0, $take );
$x = substr( $x, $take );
$mod = $a % $y;
}
while ( strlen($x) );
return (int)$mod;
}
// example
echo my_bcmod( "7044060001970316212900", 150 );
?>
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