hello rust

main.rs

use std::iter;

fn primes(maxn: uint) -> (Vec<bool>, Vec<uint>) {
    let mut primes : Vec<uint> = Vec::new();
    let mut is_prime : Vec<bool> = Vec::from_elem(maxn + 1, true);
    *is_prime.get_mut(0) = false;
    *is_prime.get_mut(1) = false;
    primes.push(2);
    for i in iter::range_step_inclusive(4, maxn, 2) {
        *is_prime.get_mut(i) = false;
    }
    let maxn_sqrt = (maxn as f64).sqrt() as uint;
    for i in iter::range_step_inclusive(3, maxn_sqrt, 2) {
        if is_prime[i] {
            primes.push(i);
            for i in iter::range_step_inclusive(i * i, maxn, i) {
                *is_prime.get_mut(i) = false;
            }
        }
    }
    for i in iter::range_step_inclusive(maxn_sqrt + 1, maxn, 2) {
        if is_prime[i] { primes.push(i); }
    }
    return (is_prime, primes);
}

fn main() {
    let maxn = 100000000u;
    let (is_prime, primes) = primes(maxn);
    println!("{} is prime: {}", maxn,  is_prime[maxn]);
    println!("number of primes: {}", primes.len());
}

result.txt

$ cargo build --release

$ time cargo run --release
     Running `target/release/euler`
100000000 is prime: false
number of primes: 5761455

real	0m1.522s
user	0m1.414s
sys	0m0.103s