feat: Add HashMap exercises

This commit is contained in:
sazid 2020-10-26 18:08:48 +06:00
parent 0c12fa31c5
commit 633c00cf80
3 changed files with 151 additions and 0 deletions

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// hashmap1.rs
// A basket of fruits in the form of a hash map needs to be defined.
// The key represents the name of the fruit and the value represents
// how many of that particular fruit is in the basket. You have to put
// at least three different types of fruits (e.g apple, banana, mango)
// in the basket and the total count of all the fruits should be at
// least five.
//
// Make me compile and pass the tests!
//
// Execute the command `rustlings hint collections3` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
fn fruit_basket() -> HashMap<String, u32> {
let mut basket = // TODO: declare your hash map here.
// Two bananas are already given for you :)
basket.insert(String::from("banana"), 2);
// TODO: Put more fruits in your basket here.
basket
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn at_least_three_types_of_fruits() {
let basket = fruit_basket();
assert!(basket.len() >= 3);
}
#[test]
fn at_least_five_fruits() {
let basket = fruit_basket();
assert!(basket
.values()
.sum::<u32>() >= 5);
}
}

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// hashmap2.rs
// A basket of fruits in the form of a hash map is given. The key
// represents the name of the fruit and the value represents how many
// of that particular fruit is in the basket. You have to put *MORE
// THAN 11* fruits in the basket. Three types of fruits - Apple (4),
// Mango (2) and Lichi (5) are already given in the basket. You are
// not allowed to insert any more of these fruits!
//
// Make me pass the tests!
//
// Execute the command `rustlings hint collections4` if you need
// hints.
// I AM NOT DONE
use std::collections::HashMap;
#[derive(Hash, PartialEq, Eq)]
enum Fruit {
Apple,
Banana,
Mango,
Lichi,
Pineapple,
}
fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
let fruit_kinds = vec![
Fruit::Apple,
Fruit::Banana,
Fruit::Mango,
Fruit::Lichi,
Fruit::Pineapple,
];
for fruit in fruit_kinds {
// TODO: Put new fruits if not already present. Note that you
// are not allowed to put any type of fruit that's already
// present!
}
}
#[cfg(test)]
mod tests {
use super::*;
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::Lichi, 5);
basket
}
#[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::Lichi).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);
}
}

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@ -400,6 +400,28 @@ Hint 1: `i` is each element from the Vec as they are being iterated.
Hint 2: Check the suggestion from the compiler error ;)
"""
[[exercises]]
name = "collections3"
path = "exercises/collections/hashmap1.rs"
mode = "test"
hint = """
Hint 1: Take a look at the return type of the function to figure out
the type for the `basket`.
Hint 2: Number of fruits should be at least 5. And you have to put
at least three different types of fruits.
"""
[[exercises]]
name = "collections4"
path = "exercises/collections/hashmap2.rs"
mode = "test"
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
"""
# MACROS
[[exercises]]