Reverse Stringeasy

fn reverse_string(s: &mut Vec<char>) {
    // TODO: reverse s in-place using two pointers
}

fn main() {
    let mut s: Vec<char> = "hello".chars().collect();
    reverse_string(&mut s);
    let result: String = s.into_iter().collect();
    println!("{}", result); // "olleh"
}