Remove leading and trailing zeroes from a list of numbers

main.rs

/// Given a non-empty array containing only non-negative integers, return the
/// list with trailing and leading zeroes removed.
///
/// Example:
///
/// ```
/// > removeZeroes([0, 0, 0, 3, 1, 4, 1, 5, 9, 0, 0, 0, 0])
/// > [3, 1, 4, 1, 5, 9]
///
/// > removeZeroes([0, 0, 0])
/// > []
///
/// > removeZeroes([8])
/// > [8]
/// ```

fn main() {
    let mut v = vec![0, 0, 0, 3, 1, 4, 1, 5, 9, 0, 0, 0, 0];
    println!("{:?}", remove_zeros(&mut v));
    println!("{:?}", v);
}

fn remove_zeros(v: &mut Vec<usize>) {
    if v.len() == 0 {
        return;
    }

    let mut i = 0;
    while i <= v.len() && v[0..i].iter().sum::<usize>() == 0 {
        i += 1;
    }

    v.drain(..i - 1);

    if v.len() == 0 {
        return;
    }

    let mut j = v.len() - 1;
    while v[j..].iter().sum::<usize>() == 0 {
        j -= 1;
    }

    v.drain(j + 1..);
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_remove_zeros() {
        let mut v = vec![0, 0, 0, 3, 1, 4, 1, 5, 9, 0, 0, 0, 0];
        remove_zeros(&mut v);
        assert_eq!(vec![3, 1, 4, 1, 5, 9], v,);

        let mut v = vec![0, 0, 0];
        remove_zeros(&mut v);
        assert_eq!(Vec::<usize>::new(), v);

        let mut v = vec![8];
        remove_zeros(&mut v);
        assert_eq!(vec![8], v);

        let mut v = vec![];
        remove_zeros(&mut v);
        assert_eq!(Vec::<usize>::new(), v);

        let mut v = vec![0];
        remove_zeros(&mut v);
        assert_eq!(Vec::<usize>::new(), v);

        let mut v = vec![1, 0, 0, 0];
        remove_zeros(&mut v);
        assert_eq!(vec![1], v);
    }
}