const INPUT: &str = "aaabcccédéééééééééééééééééé";

fn compress(s: &str) -> String {
    let mut chars: Vec<char> = vec![];
    let mut curr: Option<char> = None;
    let mut count: u32 = 0;
    for b in s.chars() {
        match curr {
            None => {
                curr = Some(b);
                count += 1;
            }
            Some(c) if b == c => {
                count += 1;
            }
            Some(c) => {
                chars.push(c);
                for c in count.to_string().chars() {
                    chars.push(c);
                }
                curr = Some(b);
                count = 1;
            }
        }
    }
    if let Some(c) = curr {
        chars.push(c);
        for c in count.to_string().chars() {
            chars.push(c);
        }
    }
    chars.into_iter().collect()
}

fn main() {
    println!("Input: {INPUT}");
    println!("Output: {:?}", compress(INPUT));
}