Step 4: The Rust version

use std::collections::HashMap;

fn count_words(text: &str) -> Vec<(String, usize)> {
    let mut counts: HashMap<String, usize> = HashMap::new();
    for word in text
        .to_lowercase()
        .split(|c: char| !c.is_alphabetic())
        .filter(|w| !w.is_empty())
    {
        *counts.entry(word.to_string()).or_insert(0) += 1;
    }
    let mut sorted: Vec<(String, usize)> = counts.into_iter().collect();
    sorted.sort_by(|a, b| b.1.cmp(&a.1).then(a.0.cmp(&b.0)));
    sorted
}

fn main() {
    let text = "The quick brown fox jumps over the lazy dog. The end!";
    for (word, count) in count_words(text) {
        println!("{:<6} {}", word, count);
    }
}

the    3
brown  1
dog    1
end    1
fox    1
jumps  1
lazy   1
over   1
quick  1