public/subjects/previousprime

prev_prime

Instructions

Write a function which returns the first prime number which is equal or inferior to the u64 passed as parameter.

If there are no primes inferior to the u64 passed as parameter the function should return 0.

Expected function

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

}

Usage

Here is a possible program to test your function :

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
$