Online PHP editor | refs for C4IlF

<?php /** * Fibonacci number creator. * * @param int $grandparent * @param int $parent * @return int */ function f(int $grandparent, int $parent): int { return intval($parent + $grandparent); } /** * A classical fibonacci range builder. * * @param int $length * @return int[] */ function builder(int $length): array { $grandparent = 0; $parent = 1; $range = [$grandparent, $parent]; for ($i = 0; $i <= $length; $i++) { $child = f($grandparent, $parent); $grandparent = $parent; $parent = $child; $range[] = $child; } return $range; } /** * Generator for fibonacci numbers. * * @param int $length * * @yields int */ function generator(int $length) { $grandparent = 0; $parent = 1; for ($i = 0; $i <= $length; $i++) { yield $child = f($grandparent, $parent); $grandparent = $parent; $parent = $child; } } $maxNumIterations = 999999; for ($numIterations = 0; $numIterations < $maxNumIterations; $numIterations++) { gc_collect_cycles(); $builderUsage = 0; foreach (builder($numIterations) as $fibonacciNumber) { $currentUsage = memory_get_usage(false); if ($currentUsage > $builderUsage) { $builderUsage = $currentUsage; } } gc_collect_cycles(); $generatorUsage = 0; foreach (generator($numIterations) as $fibonacciNumber) { $currentUsage = memory_get_usage(false); if ($currentUsage > $generatorUsage) { $generatorUsage = $currentUsage; } } echo sprintf( "#%d\tBuilder: %.2f kb\tGenerator: %.2f kb\t%d", $numIterations, $builderUsage / 1024, $generatorUsage / 1024, $fibonacciNumber ) . PHP_EOL; if ($builderUsage > $generatorUsage) { echo sprintf( 'Found difference at iteration #%d and fibonacci number %d', $numIterations, $fibonacciNumber ) . PHP_EOL; break; } }