## Programming Challenge #1 — Primes

Code difficulty: 3/10
Math difficulty: 4/10

In his challenge I ask that you do the following things:

Create a program that will:

1. Allow a user to input a number
2. Allow the user to see if the number is prime or not
3. If the number is not prime, tell the user what number it is divisible by
4. Use a function to process whether or not the value is prime (this idea will be used in a future challenge
5. Use double or Long for increased number length

Concepts used: Functions, variables, loops, arithmatic functions, breaks, boolean

You should be able to do this by: Lesson 33

My solution: http://ideone.com/AKmCm (spoilers- Don’t look unless you are really stuck!)

Please note that my solutions are not checked thoroughly, and should only be used for reference. They are often non-optimal solutions that could be improved upon (by you!). I keep these intentionally rough for just that reason.

1. MegaHertz says:

I think the example code has an off by one error. The for loops should be:

for(int i=6; i<=testUpTo; i+=6)
or
for(int i=6; i<testUpTo+1; i+=6)