Re: Prime numbers
- From: Steve Kelley <skelley@xxxxxxxxxxxxxxxxxxxxx>
- Date: Wed, 07 Dec 2005 08:31:50 -0500
new programer wrote:
I believe that any number that is not prime can be divided by either two or three. If you factor a number to the smallest factors you will (I think) always have either a 2 or 3 in the list of factors unless it is prime or the square of a prime. Someone who is more steeped in math will correct me if I'm wrong. So If my postulate is correct then...Thanks for trying to help me guys. Ok, so I understand that there is no even prime number, besides 2. And also if, you mod any even number by 2, the result will obviously be 0. But then, how do I deal with composite (non prime) numbers, that are odd.
I have come up with the following algorithm so far: If inputNum Mod 2 = 0 Then (for even non prime numbers) ' not prime elsif inputNum mod ?? = ?? Then (for odd non prime numbers) ' not prime else (for prime numbers) ' number is prime
can you guys please help me out a little more.
Thanks in advance.
isPrime = False If inputNum Mod 2 and _ inputNum Mod 3 and _ sqr(inputNum) not an Integer then isPrime = True End If
-- Steve Kelley Protean Instrument Corp. .