Recursion Error

[Tewg]

I'm having a java.lang.StackOverflowError when i run, i know its n RTP but where would my logic be off, I'm looking to find the lowest number divisable by 1, 20 inclusive.

code:

import hsa.*; public class Prob5 {     private static void tryit (int n)     {         for (int i = 1 ; i <= 20 ; i++)         {             if (n % i != 0)             {                 tryit (n + 1);             }         }         Stdout.print (n);     }     public static void main (String args[])     {         tryit (20);     } }

[Tewg]

ok i tryed it with the smaller numbers 1,10 inclusive which works, but stops 1 number before 2520 (answer) in a continuos loop and i can't for the life of me see why. I have put several output statements in to trace the execution but i still can't find the logic error.

[Tony]

Are you sure that recursion is the best method to loop here? The lowest number would be a multiple of all the largest factors (I mean factors that are not already a part of larger factors in the list), so:

11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20

= 670 442 572 800

That's a lot to stack. Assuming an unreasonably low 1 byte per stack call, you gonna need to find a computer with 670 GB of RAM.

This will probably take a while to run as well.

[Tewg]

oh I've already figured this wont work with this bg a number I'm just playing with recursion because i have little to no experience with it.

[Tony]

Tewg @ Sun Apr 13, 2008 10:33 pm wrote:

i have little to no experience with it.

It's probably helpful to know how recursion is handled by the compiler/interpreter.

[Tewg]

Yah, I'm just reading up on that now, thanks for your help.