PHP Algorithms – factorial

PHP Algorithms – factorial recursive solution

<?php
/* 
* EN factorial
*/
function fact($n){
	if($n < 1) return 1;
	$arr[$n] = $n * fact($n - 1);
	
	return $n * fact($n - 1); // 4 * 3 * 2 * 1
}

echo fact(4); // 24

PHP Algorithms – factorial none recursive solution

<?php
/* 
* EN(factorial) 
*/
function powf($n){
	$sum = $n;
	while($n - 1 > 0){
		$n--;
		$sum *= $n;
	}
	return $sum;
}

echo powf(4); // 24

<?php
/* 
* EN(factorial) 
*/
function powf($n){
	$sum = $n;
	for($i = $n; $i - 1 > 0; $i--){
		$n--;
		$sum *= $n;
	}
	
	return $sum;
}

echo powf(4); // 24