(PHP 5, PHP 7)
bcpowmod — Raise an arbitrary precision number to another, reduced by a specified modulus
$left_operand
, string $right_operand
, string $modulus
[, int $scale = 0
] )
Use the fast-exponentiation method to raise
left_operand to the power
right_operand with respect to the modulus
modulus.
left_operandThe left operand, as a string.
right_operandThe right operand, as a string.
modulusThe modulus, as a string.
scaleAcest parametru opțional este utilizat pentru a stabili numărul cifrelor după virgulă din rezultat. Dacă este omis, valoarea implicită va fi cea stabilită global cu funcția bcscale(), sau va fi 0 dacă nu a fost stabilită cu ajutorul acestei funcții.
Returns the result as a string, or NULL if modulus
is 0.
Notă:
Because this method uses the modulus operation, numbers which are not positive integers may give unexpected results.
The following two statements are functionally identical. The bcpowmod() version however, executes in less time and can accept larger parameters.
<?php
$a = bcpowmod($x, $y, $mod);
$b = bcmod(bcpow($x, $y), $mod);
// $a and $b are equal to each other.
?>