projecteuler.net/012/main_basic.rs

fn div_num(n: u32) -> u32 {
    let mut res = 0;
    for i in 1..=n {
        if n % i == 0 { res += 1; }
    }
    return res;
}

fn main() {
    let mut n = 1;
    let mut best_dn = 1;
    for k in 2..50000 {
        n += k;
        let dn = div_num(n);
        if dn > best_dn {
            best_dn = dn;
            println!("[{}]{}:{}",k, n, dn);
        }
    }
}