use std::convert::TryInto;

fn main() {
    use std::time::Instant;   //those
    let now = Instant::now(); //are

    primes_are_forever(); //not you

    let elapsed = now.elapsed(); //for
    println!("Elapsed: {:.2?}", elapsed); //benchmarking
}

fn primes_are_forever() {
    println!("2");
    println!("3");
    println!("5");
    println!("7"); //this is compensating for optimisation
    let mut is_prime = true;
    let mut vector = vec![2, 3, 5, 7,11, 13, 17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149];
    let mut i: usize = 0;
    for number_that_might_be_a_prime in (5..1000000).step_by(2) {
        let where_to_end_checking: usize = vector.len() / 10 + 1; //there is less than (number/10) primes below (number), this is why I need to print first four primes
        while i < where_to_end_checking.try_into().unwrap() {
            if number_that_might_be_a_prime % vector[i] == 0 {
                is_prime = false;
                break
            }
            i = i + 1;
        }
        if is_prime == true {
            println!("{}", number_that_might_be_a_prime);
            vector.push(number_that_might_be_a_prime);
        }
        i = 0;
        is_prime = true;
    }
}


 //old version here

 /*

fn primes_are_forever() {
    let mut number_that_might_be_a_prime_pierwsza = true;
    let mut wektor = vec![2;1000];
    let mut i: i32 = 0;
    for number_that_might_be_a_prime in 3..100 {
        let pierwiastek_liczby: i32 = number_that_might_be_a_prime.integer_sqrt() + 1;
        while i < pierwiastek_liczby {
            let i2: i32 = number_that_might_be_a_prime % &wektor[i as usize];
            if i2 == 0 {
                number_that_might_be_a_prime_pierwsza = false;
                break
            }
            i = i + 2;
        }
        if number_that_might_be_a_prime_pierwsza == true {
            println!("{}", number_that_might_be_a_prime);
            {
                wektor[0].some_value = ;



            }
            &mut wektor[i as usize] = &mut number_that_might_be_a_prime;
        }
        i = 0;
        number_that_might_be_a_prime_pierwsza = true;
    }


}
*/