2 different number input factorial using function and for loop in php

Question

I have a problem making a C(m,n)=m!/n!(m-n)! formula using a function and for loop in php, my code look like this:

<?php
function factorial($m,$n){
	$facm=$m;
	for ($i=$m-1; $i >= 1 ; $i--) { 
		$facm*=$i;
	}
	$facn=$n;
	for ($i=$n-1; $i >= 1 ; $i--) { 
		$facn*=$i;
	}
	$faco=$m-$n;
	for ($i=$m-$n; $i >= 1 ; $i--) { 
		$faco*=$i;
	}
	return $facm/$facn*$faco;
}
}

echo factorial($bilm,$biln);
?> 

but this code show wrong result, is it something wrong with my code? thank you for your attention.

Answer 1

Yes you can do like below if it is stick to 2 parameters. If the parameters are dynamically change, then pass array to the function and do a foreach there.

 <?php
    $bilm = $_POST['bilm'];
    $biln = $_POST['biln'];

    function factorial($m,$n){

            $facm=$m;
            for ($i=$m-1; $i >= 1 ; $i--) { 
                $facm*=$i;
            }

            $facn=$n;
            for ($i=$n-1; $i >= 1 ; $i--) { 
                $facn*=$i;
            }

            $facmsubn = $msubn=$m-$n;
            for ($i=$msubn-1; $i >= 1 ; $i--) { 
                $facmsubn*=$i;
            }

            return ($facm/$facn)*$facmsubn; //By assuming (m!/n!)*(m-n)!; If it is m!/(n!*(m-n)!) then change the logic as per your formula
   }
          echo factorial($bilm,$blin);
    ?>

But why you need pass 2 parameters? Calling the function twice would make sense.

Runtime environment is here http://phpfiddle.org/main/code/zkfs-21am