public/subjects/previousprime

prev_prime

Instructions

Create a function which returns the first prime number which is less than or equal to the u64 passed as an argument.

If there are no smaller primes, the function should return 0.

Expected function

pub fn prev_prime(nbr: u64) -> u64  {

}

Usage

Here is a possible program to test your function :

use previousprime::*;

fn main() {
    println!("The previous prime number before 34 is: {}", prev_prime(34));
}

And its output :

$ cargo run
The previous prime number before 34 is: 31
$