public/subjects/nextprime

nextprime

Instructions

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

The function must be optimized, so as to avoid time-outs.

We consider that only positive numbers can be prime numbers.

Expected function

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

}

Usage

Here is a possible program to test your function :

fn main() {
    println!("The next prime after 4 is: {}", next_prime(4));
    println!("The next prime after 11 is: {}", next_prime(11));
}

And its output :

$ cargo run
The next prime after 4 is: 5
The next prime after 11 is: 11
$