exer2.rs

fn hailstone(n: uint) -> uint {
    match n % 2 {
        0 => n / 2,
        _ => 3 * n + 1,
    }
}


fn hailstone_len(n: uint) -> uint {
    match n {
        1 => 0,
        _ => hailstone_len(hailstone(n)) + 1,
    }
}


fn divisors(n: int) -> Vec<int> {
    let mut ret = Vec::new();
    for i in range(2, (n / 2) + 1) {
        if n % i == 0 {
            ret.push(i);
        }
    }
    return ret;
}


fn main() {
    println!("Hailstone stuff:");
    for &n in [11, 27, 686901248, 1].iter() {
        println!("hailstone_len({}) = {}", n, hailstone_len(n));
    }
    println!("");

    println!("Divisor stuff");
    for &n in [30, 64, 127].iter() {
        println!("divisors({}) = {}", n, divisors(n));
    }
}