public/subjects/prime_checker/README.md

prime_checker

Instructions

Create a function prime_checker that takes an u32 and check if it is a prime number.

The result will be None if the argument is less or equal one, otherwise it will return a Result. If the u32 is prime, the function will return anOk(u32). For any other case it will return an enum PrimeErr. The enum PrimeErr will be Even if the number is a multiple of two or Divider(u32) where the u32 is the smallest divider of the number.

Your solution should be optimized to a certain degree.

Expected Function and structure

#[derive(PartialEq, Eq, Debug)]
pub enum PrimeErr {
    Even,
    Divider(u32),
}

pub fn prime_checker(nb: u32) ->  /* Implement return type here */ {}

Usage

Here is a program to test your function:

use prime_checker::*;

fn main() {
    println!("Is {} prime? {:?}", 2, prime_checker(2));
    println!("Is {} prime? {:?}", 14, prime_checker(14));
    println!("Is {} prime? {:?}", 2147483647, prime_checker(2147483647));
}

And its output:

$ cargo run
Is 2 prime? Some(Ok(2))
Is 14 prime? Some(Err(Even))
Is 2147483647 prime? Some(Ok(2147483647))
$