Code shared from the Rust Playground

playground.rs

fn reverse(input: &str) -> String {
    let string = input.to_string();
    string
        .split(' ')
        .map(|word| {
            if word.len() < 5 {
                word.to_string()
            } else {
                word.chars().rev().collect()
            }
        })
        .collect::<Vec<_>>()
        .join(" ")
}

fn reverse2(input: &str) -> String {
    let mut output = input.as_bytes().to_vec();
    let len = output.len();
    let mut start;
    let mut end = 0;
    for i in 0..len-1 {
        if output[i+1] == b' ' {
            start = end;
            end = i;
            if (end - start) >= 5 {
                println!("long");
                let word = &mut output[start..end];
                word.reverse();
            }
            println!(
                "{}",
                String::from_utf8(output[start..end].to_vec()).unwrap()
            );
        }
    }
    String::from_utf8(output).unwrap()
}
fn main() {
    println!("{}", reverse("Zhopa is a life worth living"));
    println!("{}", reverse2("Zhopa is a life worth living"));
}