Add word counter exercise to std-types section

src/std-types/Cargo.toml

@@ -5,7 +5,6 @@ edition = "2021"
 publish = false
 
 [dependencies]
-clap = { version = "4.4", features = ["derive"] }
 
 [[bin]]
 name = "hashset"

src/std-types/word_counter.md

@@ -4,7 +4,8 @@ minutes: 20
 
 # Exercise: Word Counter
 
-Create a program that counts the frequency of words in a given text. The program should:
+Create a program that counts the frequency of words in a given text. The program
+should:
 
 1. Take a string of text as input
 2. Split the text into words (consider words to be separated by whitespace)
@@ -16,14 +17,11 @@ Use a `HashMap` to store the word counts.
 ## Example
 
 ```rust
-fn main() {
-    let text = "the quick brown fox jumps over the lazy dog";
-    let counts = count_words(text);
-    print_word_counts(&counts);
-}
+{{#include word_counter.rs:main}}
 ```
 
 Expected output:
+
 ```
 brown: 1
 dog: 1
@@ -37,9 +35,12 @@ the: 2
 
 ## Tasks
 
-1. Implement the `count_words` function that takes a string slice and returns a `HashMap<String, u32>`
-2. Make the word counting case-insensitive (e.g., "The" and "the" count as the same word)
-3. Implement the `print_word_counts` function that prints the word counts in alphabetical order
+1. Implement the `count_words` function that takes a string slice and returns a
+   `HashMap<String, u32>`
+2. Make the word counting case-insensitive (e.g., "The" and "the" count as the
+   same word)
+3. Implement the `print_word_counts` function that prints the word counts in
+   alphabetical order
 4. Add tests for:
    - Empty input
    - Simple text with repeated words
@@ -51,43 +52,6 @@ the: 2
 2. Add statistics like total words, unique words, and average word length
 3. Find and display the most common words
 
-[View solution](word_counter_solution.md)
-
 ```rust,editable
-use std::collections::HashMap;
-
-/// WordCounter counts the frequency of words in text.
-struct WordCounter {
-    word_counts: HashMap<String, usize>,
-}
-
-impl WordCounter {
-    /// Create a new WordCounter.
-    fn new() -> Self {
-        todo!("Initialize the WordCounter")
-    }
-
-    /// Count words in the given text.
-    fn count_words(&mut self, text: &str) {
-        todo!("Implement word counting logic")
-    }
-
-    /// Get the count for a specific word.
-    fn word_count(&self, word: &str) -> usize {
-        todo!("Return the count for the given word")
-    }
-
-    /// Find the most frequent word(s) and their count.
-    fn most_frequent(&self) -> Vec<(&str, usize)> {
-        todo!("Find and return the most frequent word(s)")
-    }
-}
-
-#[test]
-fn test_word_counter() {
-    let mut counter = WordCounter::new();
-    counter.count_words("Hello world, hello Rust!");
-    assert_eq!(counter.word_count("hello"), 2);
-    assert_eq!(counter.word_count("rust"), 1);
-    assert_eq!(counter.word_count("world"), 1);
-} 
+{{#include word_counter.rs:exercise}}
+```