Burgerservicenummer Elfproef Validator

gistfile1.java

    /** Validate BSN according to http://nl.wikipedia.org/wiki/Burgerservicenummer */
    private boolean isValidBSN(int candidate) {
        if (candidate <= 9999999 || candidate > 999999999) {
            return false;
        }
        int sum = -1 * candidate % 10;

        for (int multiplier = 2; candidate > 0; multiplier++) {
            int val = (candidate /= 10) % 10;
            sum += multiplier * val;
        }

        return sum != 0 && sum % 11 == 0;
    }

Hey, I was making this code as well, and found your example code to be helpfull, thanks!

If someone else stumbles upon this, looking to use it here is my implementation of this code, it is a bit faster(19.5s > 16.3s for the first 2m numbers), but could be improved by multithreading if you'd realy want.
As i fed everyting from 100000000 to 999999999 i left out the first check.

private static void test11(int b) {
		int ans =0;
		for(int i=9;i>1;i--) {
			ans +=ComputeDigitAt(b,i);
		}
		ans +=(b/Math.pow(10, 0)%10) * -1;
		if(ans% 11==0) {
			System.out.println(b + " : " + MD5(b));
		}
	}

`private static int ComputeDigitAt(int num, int n) {
	return (int)((num / Math.pow(10, n-1)) % 10)*n;
}`

(ignore the line with MD5, that was used for my implementation, you could change the type to boolean and return true there)
Thanks, your code was much appreciated

Interesting that you started with 100000000, because the first years (everyone that transferred from the old system) these numbers had 8 digits. Those numbers got a leading zero when the length of the number was increased to 9 digits.