Project Euler yet again

[Panphobia]

I have been doing project euler a lot, it is addicting, I am stuck on making this question solution efficient http://projecteuler.net/problem=148 , I keep getting the java heap space exception or whatever, here is my code

code:

package projecteuler148; import java.util.*; import java.math.*; public class ProjectEuler148 {     /**      * @param args the command line arguments      */     public static void main(String[] args) {         BigInteger lol;         int tot = 0;         ArrayList<BigInteger>fact=new ArrayList<BigInteger>();         fact.add(BigInteger.ONE);         out:         for (int i = 0; i < Math.pow(10, 9); ++i) {             for (int x = 0; x < i + 1; ++x) {                 fact.add(BigInteger.valueOf(i+1).multiply(fact.get(i)));                 lol = fact.get(i).divide(fact.get(i - x).multiply(fact.get(x)));                 if (lol.equals(BigInteger.ZERO)) {                     continue out;                 }             }             tot++;         }         System.out.println(tot);     } }

I do not know the better solution to this, is there a more efficient way to do this than what I am doing atm?

[Insectoid]

This is a problem better solved with math than code. They're asking to check the first one billion rows specifically so your solution will not work. I suggest you study Pascal's triangle for a bit to discover any shortcuts you could take.

[Tony]

Panphobia @ Tue Jan 01, 2013 6:06 pm wrote:

BigInteger lol;

This probably doesn't matter to you, but to anyone else reading your code this naming convention works very poorly.

[Panphobia]

Ohhh yeaa sorry about that, it is kind of a short program, doesn't require it, but it isn't good programming practice I know.