feat(simple_hash): refactor completely the exercise, work in progress

subjects/simple_hash/README.md

@@ -2,18 +2,18 @@
 
 ### Instructions
 
-Create a **function** named `contain`, that checks a `HashMap` to see if it contains a given key.
+Create a **function** named `word_frequency_counter` which will receive a vector of strings (each string being a single word) and return an `HashMap` with the word as the key and the number of repetitions as the value.
 
-Create a **function** named `remove` that removes a given key from the `HashMap`.
+Also create a function named `nb_distinct_words` which will take a reference to the `HashMap` and return the number of distinct words present in it.
 
-> Pay attention to the comment in the [usage](#usage)
 
 ### Expected functions
 
 ```rust
-pub fn contain(h: &HashMap<&str, i32>, s: &str) -> bool {}
+pub fn word_frequency_counter(words: Vec<&str>) -> HashMap<&str, usize> {}
 
-pub fn remove(h: &mut HashMap<&str, i32>, s: &str) {}
+pub fn nb_distinct_words(frequency_count: &HashMap<&str, usize>) -> usize {
+}
 ```
 
 ### Usage
@@ -25,32 +25,14 @@ use simple_hash::*;
 use std::collections::HashMap;
 
 fn main() {
-    let mut hash: HashMap<&str, i32> = HashMap::new();
-    hash.insert("Daniel", 122);
-    hash.insert("Ashley", 333);
-    hash.insert("Katie", 334);
-    hash.insert("Robert", 14);
-
-    println!(
-        "Does the HashMap contains the name Roman? => {}",
-        contain(hash.clone(), "Roman")
-        //----------^^^^^^^^
-        // this is not correct, fix it to match the solution the expected function
-    );
-    println!(
-        "Does the HashMap contains the name Katie? => {}",
-        contain(hash.clone(), "Katie")
-        //----------^^^^^^^^
-        // this is not correct, fix it to match the solution the expected function
-    );
-    println!("Removing Robert {:?}", remove(hash.clone(), "Robert"));
-    println!(
-        "Does the HashMap contains the name Robert? => {}",
-        contain(hash.clone(), "Robert")
-        //----------^^^^^^^^
-        // this is not correct, fix it to match the solution the expected function
-    );
-    println!("Hash {:?}", &hash);
+    let sentence = "this is a very basic sentence with only few \
+                repetitions. once again this is very basic and \
+                but it should be enough for basic tests".to_string();
+    let words = sentence.split(" ").collect::<Vec<&str>>();
+
+    let frequency_count = word_frequency_counter(words);
+    println!("{:?}", frequency_count);
+    println!("{}", nb_distinct_words(&frequency_count));
 }
 ```
 
@@ -58,11 +40,8 @@ And its output
 
 ```console
 $ cargo run
-Does the HashMap contains the name Roman? => false
-Does the HashMap contains the name Katie? => true
-Removing Robert ()
-Does the HashMap contains the name Robert? => false
-Hash {"Katie": 334, "Daniel": 122, "Ashley": 333}
+{"tests": 1, "with": 1, "this": 2, "it": 1, "enough": 1, "is": 2, "but": 1, "sentence": 1, "only": 1, "basic": 3, "again": 1, "for": 1, "be": 1, "once": 1, "very": 2, "should": 1, "few": 1, "and": 1, "a": 1, "repetitions.": 1}
+20
 $
 ```