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Diffstat (limited to 'rust/rustlings/exercises/11_hashmaps/hashmaps2.rs')
| -rw-r--r-- | rust/rustlings/exercises/11_hashmaps/hashmaps2.rs | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/rust/rustlings/exercises/11_hashmaps/hashmaps2.rs b/rust/rustlings/exercises/11_hashmaps/hashmaps2.rs new file mode 100644 index 0000000..482db7c --- /dev/null +++ b/rust/rustlings/exercises/11_hashmaps/hashmaps2.rs @@ -0,0 +1,99 @@ +// 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 the fruits that are already in the basket (Apple, +// Mango, and Lychee). + +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 { + // This works just fine, but clippy doesn't like how readable and obvious the code is + // if !basket.contains_key(&fruit) { + // basket.insert(fruit, 10); + // } + basket.entry(fruit).or_insert(10); + } +} + +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); + } + } +} |