hashmaps2 solution

exercises/11_hashmaps/hashmaps2.rs

@@ -6,8 +6,6 @@
 // must add fruit to the basket so that there is at least one of each kind and
 // more than 11 in total - we have a lot of mouths to feed. You are not allowed
 // to insert any more of these fruits!
-//
-// Make me pass the tests!
 
 use std::collections::HashMap;
 
@@ -21,7 +19,7 @@ enum Fruit {
 }
 
 fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
-    let fruit_kinds = vec![
+    let fruit_kinds = [
         Fruit::Apple,
         Fruit::Banana,
         Fruit::Mango,
@@ -46,12 +44,8 @@ mod tests {
 
     // Don't modify this function!
     fn get_fruit_basket() -> HashMap<Fruit, u32> {
-        let mut basket = HashMap::<Fruit, u32>::new();
-        basket.insert(Fruit::Apple, 4);
-        basket.insert(Fruit::Mango, 2);
-        basket.insert(Fruit::Lychee, 5);
-
-        basket
+        let content = [(Fruit::Apple, 4), (Fruit::Mango, 2), (Fruit::Lychee, 5)];
+        HashMap::from_iter(content)
     }
 
     #[test]
@@ -81,7 +75,7 @@ mod tests {
 
     #[test]
     fn all_fruit_types_in_basket() {
-        let fruit_kinds = vec![
+        let fruit_kinds = [
             Fruit::Apple,
             Fruit::Banana,
             Fruit::Mango,
@@ -91,11 +85,12 @@ mod tests {
 
         let mut basket = get_fruit_basket();
         fruit_basket(&mut basket);
+
         for fruit_kind in fruit_kinds {
-            let amount = basket
-                .get(&fruit_kind)
-                .expect(format!("Fruit kind {:?} was not found in basket", fruit_kind).as_str());
-            assert_ne!(amount, &0);
+            let Some(amount) = basket.get(&fruit_kind) else {
+                panic!("Fruit kind {fruit_kind:?} was not found in basket");
+            };
+            assert!(*amount > 0);
         }
     }
 }

rustlings-macros/info.toml

@@ -566,8 +566,9 @@ name = "hashmaps2"
 dir = "11_hashmaps"
 hint = """
 Use the `entry()` and `or_insert()` methods of `HashMap` to achieve this.
-Learn more at https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value
-"""
+
+Learn more in The Book:
+https://doc.rust-lang.org/stable/book/ch08-03-hash-maps.html#only-inserting-a-value-if-the-key-has-no-value"""
 
 [[exercises]]
 name = "hashmaps3"

solutions/11_hashmaps/hashmaps2.rs

@@ -1 +1,95 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+// We're collecting different fruits to bake a delicious fruit cake. For this,
+// we have a basket, which we'll represent in the form of a hash map. The key
+// represents the name of each fruit we collect and the value represents how
+// many of that particular fruit we have collected. Three types of fruits -
+// Apple (4), Mango (2) and Lychee (5) are already in the basket hash map. You
+// must add fruit to the basket so that there is at least one of each kind and
+// more than 11 in total - we have a lot of mouths to feed. You are not allowed
+// to insert any more of these fruits!
+
+use std::collections::HashMap;
+
+#[derive(Hash, PartialEq, Eq, Debug)]
+enum Fruit {
+    Apple,
+    Banana,
+    Mango,
+    Lychee,
+    Pineapple,
+}
+
+fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
+    let fruit_kinds = [
+        Fruit::Apple,
+        Fruit::Banana,
+        Fruit::Mango,
+        Fruit::Lychee,
+        Fruit::Pineapple,
+    ];
+
+    for fruit in fruit_kinds {
+        // If fruit doesn't exist, insert it with some value.
+        basket.entry(fruit).or_insert(5);
+    }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // Don't modify this function!
+    fn get_fruit_basket() -> HashMap<Fruit, u32> {
+        let content = [(Fruit::Apple, 4), (Fruit::Mango, 2), (Fruit::Lychee, 5)];
+        HashMap::from_iter(content)
+    }
+
+    #[test]
+    fn test_given_fruits_are_not_modified() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        assert_eq!(*basket.get(&Fruit::Apple).unwrap(), 4);
+        assert_eq!(*basket.get(&Fruit::Mango).unwrap(), 2);
+        assert_eq!(*basket.get(&Fruit::Lychee).unwrap(), 5);
+    }
+
+    #[test]
+    fn at_least_five_types_of_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count_fruit_kinds = basket.len();
+        assert!(count_fruit_kinds >= 5);
+    }
+
+    #[test]
+    fn greater_than_eleven_fruits() {
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+        let count = basket.values().sum::<u32>();
+        assert!(count > 11);
+    }
+
+    #[test]
+    fn all_fruit_types_in_basket() {
+        let fruit_kinds = [
+            Fruit::Apple,
+            Fruit::Banana,
+            Fruit::Mango,
+            Fruit::Lychee,
+            Fruit::Pineapple,
+        ];
+
+        let mut basket = get_fruit_basket();
+        fruit_basket(&mut basket);
+
+        for fruit_kind in fruit_kinds {
+            let Some(amount) = basket.get(&fruit_kind) else {
+                panic!("Fruit kind {fruit_kind:?} was not found in basket");
+            };
+            assert!(*amount > 0);
+        }
+    }
+}