Question

So I am on ps1pr2. Through reading here, I figured out the first problem and here is my code. I tweaked it a little to fit the second problem and let the user input to what prime is being calculated:


http://codepad.org/ALTEQij0

My next question is what should my next step be? I am at a bit of a loss as how to calculate the sums of the logs. Should I assign a new variable (sumoflog), and then just keep adding to that as I work through the prime numbers?

Answer 1

Sorry, I used "answer" as a variable in my additional code that lets the user put in a number. Makes is a little confusing.

thats better:
http://codepad.org/o98NeR9d

Answer 2

Yes. Start a new variable at the beginning of your program that will keep track of the sum of the logs of the prime numbers. Since you assume that 3 is already a prime number, you should set the variable initially as:

sumoflog=log(3)

as you cycle through the primes sumoflog should increase

sumoflog=log(3)+log(5)+log(7)...

you will use a statement such as

sumoflog+=log(n) where n is a number that you have determined is a prime

Answer 3

Thanks for the heads up malpaso. As I was writing my question it began to make more sense, but your additional explanation will really help me out.

Answer 4

I misread your program. You assume that 2 is a prime and test for 3. So initially you would set:

sumoflog=log(2)

Answer 5

Cool. Thanks!

Answer 6

Got it cleared up. Any suggestions welcome:


http://codepad.org/QGEu30fc

Answer 7

You could improve the readability by changing the lines:
if divisor<(number)
if divisor>=(number)
with the structure if ... else
Otherwise good job

Answer 8

Thanks Maitre