hello.rs

fn remove_first<T:Eq + Clone>(i: T, v: Vec<T>) -> Vec<T> {
    let index = v.iter().position(|x| *x == i);

    let mut result = vec![];

    if index != None {
        if index.unwrap() > 0 {
            result.extend(v[0 .. index.unwrap()].to_vec());
        }

        result.extend(v[index.unwrap() + 1 .. v.len()].to_vec());
    } else {
        result.extend(v);
    }

    return result;
}

fn overlap<T: Eq + Clone>(a: Vec<T>, b: Vec<T>) -> Vec<T> {
    let mut result = a;

    for n in b.iter() {
        result = remove_first(n.clone(), result);
    }

    result.extend(b);

    return result;
}

fn main() {
    let mut a = vec![1, 1, 2, 3, 5, 5, 5];
    let mut b = vec![1, 1, 2, 2, 3, 4, 5, 5];
    let mut o = vec![];
     
    let expected = [1, 1, 2, 2, 3, 4, 5, 5, 5];
    o = overlap(a.clone(), b.clone());
    o.sort();
    assert_eq!(o, expected);
}