Hello guys. I need an idea. How can I calculate GCF of many numbers? I thought I could calculate two by two numbers, but it not seems to be a very effective idea. There is my function:

int gcf (unsigned int x, unsigned int y)
{
return (y == 0) ? x : gcf (y, x % y);
}

EDIT: Original suggestion was silly... revised:
Use the same technique, but don't use recursion like that. It should be able to outperform most prime number based algorithms (plus it's simpler).

Also, how are you 'folding' the method over all of the numbers?

You do not need to use seive algo here at all. Prime factors of a number can be found in sqrt(n) without the seive. You can store the count of each prime factor in an array. Initialize the HCF with the first number. Then if count of any of the prime factors(say p) for the next(and subsequent numbers) becomes less than what is in the array, update the array and divide the hcf by: p^(difference between what is in the array and the current count).

The total complexity of this algo will be: (sum of sqrt of all numbers) * (some log term - due to power - calculated in logn).

Hi, as I was told that my code doesn’t scale well at all, I thought perhaps I’d try to get a better understanding of interfaces/abstract classes and classes and the relationship between them.
I don’t want at this stage work on a big separate project as I've already got plenty ...

OK, so HostGator for some reason no longer allows gcc/g++ access unless you have a Designated Server account, which is a lot of money to spend just to compile my "Hello World" program. Thus I figured I'd compile at home, then upload. Program is your regular old bare-bones Hello World ...

Hi. I have a form with list box : lst_product, datagridview : grd_order and button: btn_addline. lst_product has a list of product ids selected from database (MS Acess 2013) , grd_order is by default empty except for 2 headers and btn_addline adds rows to grd_order.