Finding a factorial with LSL

Hi,

Anybody have a simple LSL function to find a Factorial, I can't find anything in the wiki or library. If not I guess i'll have to write one but im not sure how efficiant I can make it

a factorial function is a classic recursive function :

integer factorial(integer n)
{
if ( n == 1 )
return(1);
else return( n * factorial(n-1) );
}

You may run out of stack space with large values of n... If that is a potential problem, then use the more straightforward, but certainly less elegant :

integer factorial(integer n)
{
integer i;
integer product = 1;

for( i = n; i > 1; i-- )
product = product * i;

return ( product );
}

Thanks Ace,
I was worried about useing the recursive method as I have seen warnings about ressursion in LSL, however, this is what I tried.

integer fact(integer x)
{
  if (x <= 1)
    {
      return 1;
    }
  else
    {
      return x * fact (x - 1);
    }
}

default
{
	state_entry()
	{
		llListen(PUBLIC_CHANNEL,"",NULL_KEY,"");
	}
	listen(integer channel, string name, key id, string message)
	{
		llOwnerSay((string)fact((integer)message));
	}
}
CODE


to my supprise it worked and was a reasonable speed but the range was not good.
I then used a modified version of your second code like this

CODE

float fact(integer n)
{float product = 1;for( ; n > 1; n-- ) product = product * n;
return product;}

default
{
	state_entry()
	{
		llListen(PUBLIC_CHANNEL,"",NULL_KEY,"");
	}
	listen(integer channel, string name, key id, string message)
	{
		llOwnerSay((string)fact((integer)message));
	}
}
CODE


To my absalute amazement it has a greater range than my calulator which overflows at !69, so I can't validate the results but it apeares to work up to !170 returned value is 7257415615308000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.000000
!171 returns Infinity :) lsl is more powerfull than i give it credit for some times.

Thanks Ace :)