rust/armstrong-numbers/src/lib.rs


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fn digits(mut n: u32) -> (usize,Vec<u32>) {
    let mut v = vec![];
    while n > 9 {
        v.push(n % 10);
        n /= 10;
    }
    v.push(n);
    (v.len(),v)
}

pub fn is_armstrong_number(num: u32) -> bool {
    let (l,v) = digits(num);
    v.iter().map(|x| x.pow(l as u32)).sum::<u32>() == num
}