zlibproxy/vendor/workerman/validation/library/Rules/Fibonacci.php
2023-01-02 19:56:44 +08:00

46 lines
1.0 KiB
PHP

<?php
/*
* This file is part of Respect/Validation.
*
* (c) Alexandre Gomes Gaigalas <alexandre@gaigalas.net>
*
* For the full copyright and license information, please view the LICENSE file
* that was distributed with this source code.
*/
declare(strict_types=1);
namespace Respect\Validation\Rules;
use function is_numeric;
/**
* Validates whether the input follows the Fibonacci integer sequence.
*
* @author Danilo Correa <danilosilva87@gmail.com>
* @author Henrique Moody <henriquemoody@gmail.com>
* @author Samuel Heinzmann <samuel.heinzmann@swisscom.com>
*/
final class Fibonacci extends AbstractRule
{
/**
* {@inheritDoc}
*/
public function validate($input): bool
{
if (!is_numeric($input)) {
return false;
}
$sequence = [0, 1];
$position = 1;
while ($input > $sequence[$position]) {
++$position;
$sequence[$position] = $sequence[$position - 1] + $sequence[$position - 2];
}
return $sequence[$position] === (int) $input;
}
}