rustlings: move to rust/

120 files changed, 0 insertions, 3911 deletions

diff --git a/rustlings/exercises/00_intro/README.md b/rustlings/exercises/00_intro/README.md
deleted file mode 100644
index d32e4a8..0000000
--- a/rustlings/exercises/00_intro/README.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Intro
-
-Rust uses the `print!` and `println!` macros to print text to the console.
-
-## Further information
-
-- [Hello World](https://doc.rust-lang.org/rust-by-example/hello.html)
-- [Formatted print](https://doc.rust-lang.org/rust-by-example/hello/print.html)
diff --git a/rustlings/exercises/00_intro/intro1.rs b/rustlings/exercises/00_intro/intro1.rs
deleted file mode 100644
index 440ae83..0000000
--- a/rustlings/exercises/00_intro/intro1.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-// TODO: We sometimes encourage you to keep trying things on a given exercise
-// even after you already figured it out. If you got everything working and feel
-// ready for the next exercise, enter `n` in the terminal.
-//
-// The exercise file will be reloaded when you change one of the lines below!
-// Try adding a new `println!` and check the updated output in the terminal.
-
-fn main() {
-    println!(r#"       Welcome to...                      "#);
-    println!(r#"                 _   _ _                  "#);
-    println!(r#"  _ __ _   _ ___| |_| (_)_ __   __ _ ___  "#);
-    println!(r#" | '__| | | / __| __| | | '_ \ / _` / __| "#);
-    println!(r#" | |  | |_| \__ \ |_| | | | | | (_| \__ \ "#);
-    println!(r#" |_|   \__,_|___/\__|_|_|_| |_|\__, |___/ "#);
-    println!(r#"                               |___/      "#);
-    println!();
-    println!("This exercise compiles successfully. The remaining exercises contain a compiler");
-    println!("or logic error. The central concept behind Rustlings is to fix these errors and");
-    println!("solve the exercises. Good luck!");
-    println!();
-    println!("The file of this exercise is `exercises/00_intro/intro1.rs`. Have a look!");
-    println!("The current exercise path will be always shown under the progress bar.");
-    println!("You can click on the path to open the exercise file in your editor.");
-    println!();
-    println!("New line");
-    println!(  "   another line   ");
-    println!(r#"   yet another line"#);
-}
diff --git a/rustlings/exercises/00_intro/intro2.rs b/rustlings/exercises/00_intro/intro2.rs
deleted file mode 100644
index e0b5e27..0000000
--- a/rustlings/exercises/00_intro/intro2.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn main() {
-    println!("Hello world!");
-}
diff --git a/rustlings/exercises/01_variables/README.md b/rustlings/exercises/01_variables/README.md
deleted file mode 100644
index 5ba2efc..0000000
--- a/rustlings/exercises/01_variables/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Variables
-
-In Rust, variables are immutable by default.
-When a variable is immutable, once a value is bound to a name, you can't change that value.
-You can make them mutable by adding `mut` in front of the variable name.
-
-## Further information
-
-- [Variables and Mutability](https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html)
diff --git a/rustlings/exercises/01_variables/variables1.rs b/rustlings/exercises/01_variables/variables1.rs
deleted file mode 100644
index 2df7df8..0000000
--- a/rustlings/exercises/01_variables/variables1.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-fn main() {
-    let x = 5;
-
-    println!("x has the value {x}");
-}
diff --git a/rustlings/exercises/01_variables/variables2.rs b/rustlings/exercises/01_variables/variables2.rs
deleted file mode 100644
index b35a0bf..0000000
--- a/rustlings/exercises/01_variables/variables2.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn main() {
-    let x = 10;
-
-    if x == 10 {
-        println!("x is ten!");
-    } else {
-        println!("x is not ten!");
-    }
-}
diff --git a/rustlings/exercises/01_variables/variables3.rs b/rustlings/exercises/01_variables/variables3.rs
deleted file mode 100644
index 47b2be4..0000000
--- a/rustlings/exercises/01_variables/variables3.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-fn main() {
-    let x = 10;
-
-    println!("Number {x}");
-}
diff --git a/rustlings/exercises/01_variables/variables4.rs b/rustlings/exercises/01_variables/variables4.rs
deleted file mode 100644
index d2967ea..0000000
--- a/rustlings/exercises/01_variables/variables4.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-fn main() {
-    let mut x = 3;
-    println!("Number {x}");
-
-    x = 5; // Don't change this line
-    println!("Number {x}");
-}
diff --git a/rustlings/exercises/01_variables/variables5.rs b/rustlings/exercises/01_variables/variables5.rs
deleted file mode 100644
index be94598..0000000
--- a/rustlings/exercises/01_variables/variables5.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-fn main() {
-    let number = "T-H-R-E-E"; // Don't change this line
-    println!("Spell a number: {number}");
-
-    let number = 3;
-    println!("Number plus two is: {}", number + 2);
-}
diff --git a/rustlings/exercises/01_variables/variables6.rs b/rustlings/exercises/01_variables/variables6.rs
deleted file mode 100644
index c40e572..0000000
--- a/rustlings/exercises/01_variables/variables6.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-const NUMBER: i32 = 3;
-
-fn main() {
-    println!("Number: {NUMBER}");
-}
diff --git a/rustlings/exercises/02_functions/README.md b/rustlings/exercises/02_functions/README.md
deleted file mode 100644
index 6662d0d..0000000
--- a/rustlings/exercises/02_functions/README.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Functions
-
-Here, you'll learn how to write functions and how the Rust compiler can help you debug errors even
-in more complex code.
-
-## Further information
-
-- [How Functions Work](https://doc.rust-lang.org/book/ch03-03-how-functions-work.html)
diff --git a/rustlings/exercises/02_functions/functions1.rs b/rustlings/exercises/02_functions/functions1.rs
deleted file mode 100644
index 5dbae07..0000000
--- a/rustlings/exercises/02_functions/functions1.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-fn call_me() {
-    println!("call_me()");
-}
-
-fn main() {
-    call_me(); // Don't change this line
-}
diff --git a/rustlings/exercises/02_functions/functions2.rs b/rustlings/exercises/02_functions/functions2.rs
deleted file mode 100644
index 27f2cc7..0000000
--- a/rustlings/exercises/02_functions/functions2.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn call_me(num: u32) {
-    for i in 0..num {
-        println!("Ring! Call number {}", i + 1);
-    }
-}
-
-fn main() {
-    call_me(3);
-}
diff --git a/rustlings/exercises/02_functions/functions3.rs b/rustlings/exercises/02_functions/functions3.rs
deleted file mode 100644
index 88dff5b..0000000
--- a/rustlings/exercises/02_functions/functions3.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn call_me(num: u8) {
-    for i in 0..num {
-        println!("Ring! Call number {}", i + 1);
-    }
-}
-
-fn main() {
-    call_me(3);
-}
diff --git a/rustlings/exercises/02_functions/functions4.rs b/rustlings/exercises/02_functions/functions4.rs
deleted file mode 100644
index 2c5a3b0..0000000
--- a/rustlings/exercises/02_functions/functions4.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-fn is_even(num: i64) -> bool {
-    num % 2 == 0
-}
-
-// TODO: Fix the function signature.
-fn sale_price(price: i64) -> i64 {
-    if is_even(price) {
-        price - 10
-    } else {
-        price - 3
-    }
-}
-
-fn main() {
-    let original_price = 51;
-    println!("Your sale price is {}", sale_price(original_price));
-}
diff --git a/rustlings/exercises/02_functions/functions5.rs b/rustlings/exercises/02_functions/functions5.rs
deleted file mode 100644
index 024010f..0000000
--- a/rustlings/exercises/02_functions/functions5.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-fn square(num: i32) -> i32 {
-    num * num
-}
-
-fn main() {
-    let answer = square(3);
-    println!("The square of 3 is {answer}");
-}
diff --git a/rustlings/exercises/03_if/README.md b/rustlings/exercises/03_if/README.md
deleted file mode 100644
index b52c392..0000000
--- a/rustlings/exercises/03_if/README.md
+++ /dev/null
@@ -1,7 +0,0 @@
-# If
-
-`if`, the most basic (but still surprisingly versatile!) type of control flow, is what you'll learn here.
-
-## Further information
-
-- [Control Flow - if expressions](https://doc.rust-lang.org/book/ch03-05-control-flow.html#if-expressions)
diff --git a/rustlings/exercises/03_if/if1.rs b/rustlings/exercises/03_if/if1.rs
deleted file mode 100644
index 079c671..0000000
--- a/rustlings/exercises/03_if/if1.rs
+++ /dev/null
@@ -1,32 +0,0 @@
-fn bigger(a: i32, b: i32) -> i32 {
-    if a > b {
-        a
-    } else {
-        b
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-// Don't mind this for now :)
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn ten_is_bigger_than_eight() {
-        assert_eq!(10, bigger(10, 8));
-    }
-
-    #[test]
-    fn fortytwo_is_bigger_than_thirtytwo() {
-        assert_eq!(42, bigger(32, 42));
-    }
-
-    #[test]
-    fn equal_numbers() {
-        assert_eq!(42, bigger(42, 42));
-    }
-}
diff --git a/rustlings/exercises/03_if/if2.rs b/rustlings/exercises/03_if/if2.rs
deleted file mode 100644
index 8104487..0000000
--- a/rustlings/exercises/03_if/if2.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-// TODO: Fix the compiler error on this function.
-fn picky_eater(food: &str) -> &str {
-    if food == "strawberry" {
-        "Yummy!"
-    } else if food == "potato" {
-        "I guess I can eat that."
-    } else {
-        "No thanks!"
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-// TODO: Read the tests to understand the desired behavior.
-// Make all tests pass without changing them.
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn yummy_food() {
-        // This means that calling `picky_eater` with the argument "strawberry" should return "Yummy!".
-        assert_eq!(picky_eater("strawberry"), "Yummy!");
-    }
-
-    #[test]
-    fn neutral_food() {
-        assert_eq!(picky_eater("potato"), "I guess I can eat that.");
-    }
-
-    #[test]
-    fn default_disliked_food() {
-        assert_eq!(picky_eater("broccoli"), "No thanks!");
-        assert_eq!(picky_eater("gummy bears"), "No thanks!");
-        assert_eq!(picky_eater("literally anything"), "No thanks!");
-    }
-}
diff --git a/rustlings/exercises/03_if/if3.rs b/rustlings/exercises/03_if/if3.rs
deleted file mode 100644
index fee96f8..0000000
--- a/rustlings/exercises/03_if/if3.rs
+++ /dev/null
@@ -1,52 +0,0 @@
-fn animal_habitat(animal: &str) -> &str {
-    let identifier = if animal == "crab" {
-        1
-    } else if animal == "gopher" {
-        2
-    } else if animal == "snake" {
-        3
-    } else {
-        0
-    };
-
-    // Don't change the expression below!
-    if identifier == 1 {
-        "Beach"
-    } else if identifier == 2 {
-        "Burrow"
-    } else if identifier == 3 {
-        "Desert"
-    } else {
-        "Unknown"
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-// Don't change the tests!
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn gopher_lives_in_burrow() {
-        assert_eq!(animal_habitat("gopher"), "Burrow")
-    }
-
-    #[test]
-    fn snake_lives_in_desert() {
-        assert_eq!(animal_habitat("snake"), "Desert")
-    }
-
-    #[test]
-    fn crab_lives_on_beach() {
-        assert_eq!(animal_habitat("crab"), "Beach")
-    }
-
-    #[test]
-    fn unknown_animal() {
-        assert_eq!(animal_habitat("dinosaur"), "Unknown")
-    }
-}
diff --git a/rustlings/exercises/04_primitive_types/README.md b/rustlings/exercises/04_primitive_types/README.md
deleted file mode 100644
index d67668a..0000000
--- a/rustlings/exercises/04_primitive_types/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Primitive Types
-
-Rust has a couple of basic types that are directly implemented into the
-compiler. In this section, we'll go through the most important ones.
-
-## Further information
-
-- [Data Types](https://doc.rust-lang.org/book/ch03-02-data-types.html)
-- [The Slice Type](https://doc.rust-lang.org/book/ch04-03-slices.html)
diff --git a/rustlings/exercises/04_primitive_types/primitive_types1.rs b/rustlings/exercises/04_primitive_types/primitive_types1.rs
deleted file mode 100644
index 778c0f6..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types1.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Booleans (`bool`)
-
-fn main() {
-    let is_morning = true;
-    if is_morning {
-        println!("Good morning!");
-    }
-
-    let is_evening = !is_morning;
-    if is_evening {
-        println!("Good evening!");
-    }
-}
diff --git a/rustlings/exercises/04_primitive_types/primitive_types2.rs b/rustlings/exercises/04_primitive_types/primitive_types2.rs
deleted file mode 100644
index a45f84d..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types2.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-// Characters (`char`)
-
-fn main() {
-    // Note the _single_ quotes, these are different from the double quotes
-    // you've been seeing around.
-    let my_first_initial = 'C';
-    if my_first_initial.is_alphabetic() {
-        println!("Alphabetical!");
-    } else if my_first_initial.is_numeric() {
-        println!("Numerical!");
-    } else {
-        println!("Neither alphabetic nor numeric!");
-    }
-
-    let your_character = '😉';
-    if your_character.is_alphabetic() {
-        println!("Alphabetical!");
-    } else if your_character.is_numeric() {
-        println!("Numerical!");
-    } else {
-        println!("Neither alphabetic nor numeric!");
-    }
-}
diff --git a/rustlings/exercises/04_primitive_types/primitive_types3.rs b/rustlings/exercises/04_primitive_types/primitive_types3.rs
deleted file mode 100644
index c5a259d..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types3.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-fn main() {
-    let a = [0; 1000];
-
-    if a.len() >= 100 {
-        println!("Wow, that's a big array!");
-    } else {
-        println!("Meh, I eat arrays like that for breakfast.");
-        panic!("Array not big enough, more elements needed");
-    }
-}
diff --git a/rustlings/exercises/04_primitive_types/primitive_types4.rs b/rustlings/exercises/04_primitive_types/primitive_types4.rs
deleted file mode 100644
index 81af3e2..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types4.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn slice_out_of_array() {
-        let a = [1, 2, 3, 4, 5];
-
-        let nice_slice = &a[1..4];
-
-        assert_eq!([2, 3, 4], nice_slice);
-    }
-}
diff --git a/rustlings/exercises/04_primitive_types/primitive_types5.rs b/rustlings/exercises/04_primitive_types/primitive_types5.rs
deleted file mode 100644
index a3e60d8..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types5.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-fn main() {
-    let cat = ("Furry McFurson", 3.5);
-
-    let (name, age) = cat;
-
-    println!("{name} is {age} years old");
-}
diff --git a/rustlings/exercises/04_primitive_types/primitive_types6.rs b/rustlings/exercises/04_primitive_types/primitive_types6.rs
deleted file mode 100644
index dec639a..0000000
--- a/rustlings/exercises/04_primitive_types/primitive_types6.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn indexing_tuple() {
-        let numbers = (1, 2, 3);
-
-        let second = numbers.1;
-
-        assert_eq!(second, 2, "This is not the 2nd number in the tuple!");
-    }
-}
diff --git a/rustlings/exercises/05_vecs/README.md b/rustlings/exercises/05_vecs/README.md
deleted file mode 100644
index e1b6128..0000000
--- a/rustlings/exercises/05_vecs/README.md
+++ /dev/null
@@ -1,17 +0,0 @@
-# Vectors
-
-Vectors are one of the most-used Rust data structures. In other programming
-languages, they'd simply be called Arrays, but since Rust operates on a
-bit of a lower level, an array in Rust is stored on the stack (meaning it
-can't grow or shrink, and the size needs to be known at compile time),
-and a Vector is stored in the heap (where these restrictions do not apply).
-
-Vectors are a bit of a later chapter in the book, but we think that they're
-useful enough to talk about them a bit earlier. We shall be talking about
-the other useful data structure, hash maps, later.
-
-## Further information
-
-- [Storing Lists of Values with Vectors](https://doc.rust-lang.org/book/ch08-01-vectors.html)
-- [`iter_mut`](https://doc.rust-lang.org/std/primitive.slice.html#method.iter_mut)
-- [`map`](https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.map)
diff --git a/rustlings/exercises/05_vecs/vecs1.rs b/rustlings/exercises/05_vecs/vecs1.rs
deleted file mode 100644
index f976c84..0000000
--- a/rustlings/exercises/05_vecs/vecs1.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-fn array_and_vec() -> ([i32; 4], Vec<i32>) {
-    let a = [10, 20, 30, 40]; // Array
-
-    let v = vec![10, 20, 30, 40];
-
-    (a, v)
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_array_and_vec_similarity() {
-        let (a, v) = array_and_vec();
-        assert_eq!(a, *v);
-    }
-}
diff --git a/rustlings/exercises/05_vecs/vecs2.rs b/rustlings/exercises/05_vecs/vecs2.rs
deleted file mode 100644
index 1ec77f7..0000000
--- a/rustlings/exercises/05_vecs/vecs2.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-fn vec_loop(input: &[i32]) -> Vec<i32> {
-    let mut output = Vec::new();
-
-    for element in input {
-        // TODO: Multiply each element in the `input` slice by 2 and push it to
-        // the `output` vector.
-        output.push(element * 2);
-    }
-
-    output
-}
-
-fn vec_map_example(input: &[i32]) -> Vec<i32> {
-    // An example of collecting a vector after mapping.
-    // We map each element of the `input` slice to its value plus 1.
-    // If the input is `[1, 2, 3]`, the output is `[2, 3, 4]`.
-    input.iter().map(|element| element + 1).collect()
-}
-
-fn vec_map(input: &[i32]) -> Vec<i32> {
-    // TODO: Here, we also want to multiply each element in the `input` slice
-    // by 2, but with iterator mapping instead of manually pushing into an empty
-    // vector.
-    // See the example in the function `vec_map_example` above.
-    input
-        .iter()
-        .map(|element| {
-            element * 2
-        })
-        .collect()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_vec_loop() {
-        let input = [2, 4, 6, 8, 10];
-        let ans = vec_loop(&input);
-        assert_eq!(ans, [4, 8, 12, 16, 20]);
-    }
-
-    #[test]
-    fn test_vec_map_example() {
-        let input = [1, 2, 3];
-        let ans = vec_map_example(&input);
-        assert_eq!(ans, [2, 3, 4]);
-    }
-
-    #[test]
-    fn test_vec_map() {
-        let input = [2, 4, 6, 8, 10];
-        let ans = vec_map(&input);
-        assert_eq!(ans, [4, 8, 12, 16, 20]);
-    }
-}
diff --git a/rustlings/exercises/06_move_semantics/README.md b/rustlings/exercises/06_move_semantics/README.md
deleted file mode 100644
index 54ddd8e..0000000
--- a/rustlings/exercises/06_move_semantics/README.md
+++ /dev/null
@@ -1,10 +0,0 @@
-# Move Semantics
-
-These exercises are adapted from [pnkfelix](https://github.com/pnkfelix)'s [Rust Tutorial](https://pnkfelix.github.io/rust-examples-icfp2014/) -- Thank you Felix!!!
-
-## Further information
-
-For this section, the book links are especially important.
-
-- [Ownership](https://doc.rust-lang.org/book/ch04-01-what-is-ownership.html)
-- [Reference and borrowing](https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html)
diff --git a/rustlings/exercises/06_move_semantics/move_semantics1.rs b/rustlings/exercises/06_move_semantics/move_semantics1.rs
deleted file mode 100644
index 9385f28..0000000
--- a/rustlings/exercises/06_move_semantics/move_semantics1.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
-
-    vec.push(88);
-
-    vec
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn move_semantics1() {
-        let vec0 = vec![22, 44, 66];
-        let vec1 = fill_vec(vec0);
-        assert_eq!(vec1, vec![22, 44, 66, 88]);
-    }
-}
diff --git a/rustlings/exercises/06_move_semantics/move_semantics2.rs b/rustlings/exercises/06_move_semantics/move_semantics2.rs
deleted file mode 100644
index e205b81..0000000
--- a/rustlings/exercises/06_move_semantics/move_semantics2.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
-
-    vec.push(88);
-
-    vec
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    // TODO: Make both vectors `vec0` and `vec1` accessible at the same time to
-    // fix the compiler error in the test.
-    #[test]
-    fn move_semantics2() {
-        let vec0 = vec![22, 44, 66];
-
-        let vec1 = fill_vec(vec0.clone());
-
-        assert_eq!(vec0, [22, 44, 66]);
-        assert_eq!(vec1, [22, 44, 66, 88]);
-    }
-}
diff --git a/rustlings/exercises/06_move_semantics/move_semantics3.rs b/rustlings/exercises/06_move_semantics/move_semantics3.rs
deleted file mode 100644
index 4a90c21..0000000
--- a/rustlings/exercises/06_move_semantics/move_semantics3.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-// TODO: Fix the compiler error in the function without adding any new line.
-fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
-    vec.push(88);
-
-    vec
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn move_semantics3() {
-        let vec0 = vec![22, 44, 66];
-        let vec1 = fill_vec(vec0);
-        assert_eq!(vec1, [22, 44, 66, 88]);
-    }
-}
diff --git a/rustlings/exercises/06_move_semantics/move_semantics4.rs b/rustlings/exercises/06_move_semantics/move_semantics4.rs
deleted file mode 100644
index 89b412f..0000000
--- a/rustlings/exercises/06_move_semantics/move_semantics4.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    // TODO: Fix the compiler errors only by reordering the lines in the test.
-    // Don't add, change or remove any line.
-    #[test]
-    fn move_semantics4() {
-        let mut x = Vec::new();
-        let y = &mut x;
-        y.push(42);
-        let z = &mut x;
-        z.push(13);
-        assert_eq!(x, [42, 13]);
-    }
-}
diff --git a/rustlings/exercises/06_move_semantics/move_semantics5.rs b/rustlings/exercises/06_move_semantics/move_semantics5.rs
deleted file mode 100644
index 78d8c77..0000000
--- a/rustlings/exercises/06_move_semantics/move_semantics5.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-#![allow(clippy::ptr_arg)]
-
-// TODO: Fix the compiler errors without changing anything except adding or
-// removing references (the character `&`).
-
-// Shouldn't take ownership
-fn get_char(data: &String) -> char {
-    data.chars().last().unwrap()
-}
-
-// Should take ownership
-fn string_uppercase(mut data: String) {
-    data = data.to_uppercase();
-
-    println!("{data}");
-}
-
-fn main() {
-    let data = "Rust is great!".to_string();
-
-    get_char(&data);
-
-    string_uppercase(data);
-}
diff --git a/rustlings/exercises/07_structs/README.md b/rustlings/exercises/07_structs/README.md
deleted file mode 100644
index 3fc1fdc..0000000
--- a/rustlings/exercises/07_structs/README.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Structs
-
-Rust has three struct types: a classic C struct, a tuple struct, and a unit struct.
-
-## Further information
-
-- [Structures](https://doc.rust-lang.org/book/ch05-01-defining-structs.html)
-- [Method Syntax](https://doc.rust-lang.org/book/ch05-03-method-syntax.html)
diff --git a/rustlings/exercises/07_structs/structs1.rs b/rustlings/exercises/07_structs/structs1.rs
deleted file mode 100644
index 8376a98..0000000
--- a/rustlings/exercises/07_structs/structs1.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-struct ColorRegularStruct {
-    red: u8,
-    green: u8,
-    blue: u8,
-}
-
-struct ColorTupleStruct(u8, u8, u8);
-
-#[derive(Debug)]
-struct UnitStruct;
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn regular_structs() {
-        let green = ColorRegularStruct {
-            red: 0,
-            green: 255,
-            blue: 0,
-        };
-
-        assert_eq!(green.red, 0);
-        assert_eq!(green.green, 255);
-        assert_eq!(green.blue, 0);
-    }
-
-    #[test]
-    fn tuple_structs() {
-        let green = ColorTupleStruct(0, 255, 0 );
-
-        assert_eq!(green.0, 0);
-        assert_eq!(green.1, 255);
-        assert_eq!(green.2, 0);
-    }
-
-    #[test]
-    fn unit_structs() {
-        let unit_struct = UnitStruct;
-
-        let message = format!("{unit_struct:?}s are fun!");
-
-        assert_eq!(message, "UnitStructs are fun!");
-    }
-}
diff --git a/rustlings/exercises/07_structs/structs2.rs b/rustlings/exercises/07_structs/structs2.rs
deleted file mode 100644
index 2539e31..0000000
--- a/rustlings/exercises/07_structs/structs2.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-#[derive(Debug)]
-struct Order {
-    name: String,
-    year: u32,
-    made_by_phone: bool,
-    made_by_mobile: bool,
-    made_by_email: bool,
-    item_number: u32,
-    count: u32,
-}
-
-fn create_order_template() -> Order {
-    Order {
-        name: String::from("Bob"),
-        year: 2019,
-        made_by_phone: false,
-        made_by_mobile: false,
-        made_by_email: true,
-        item_number: 123,
-        count: 0,
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn your_order() {
-        let order_template = create_order_template();
-
-        let your_order = Order {
-            name: String::from("Hacker in Rust"),
-            count: 1,
-            ..order_template
-        };
-
-        assert_eq!(your_order.name, "Hacker in Rust");
-        assert_eq!(your_order.year, order_template.year);
-        assert_eq!(your_order.made_by_phone, order_template.made_by_phone);
-        assert_eq!(your_order.made_by_mobile, order_template.made_by_mobile);
-        assert_eq!(your_order.made_by_email, order_template.made_by_email);
-        assert_eq!(your_order.item_number, order_template.item_number);
-        assert_eq!(your_order.count, 1);
-    }
-}
diff --git a/rustlings/exercises/07_structs/structs3.rs b/rustlings/exercises/07_structs/structs3.rs
deleted file mode 100644
index d24da27..0000000
--- a/rustlings/exercises/07_structs/structs3.rs
+++ /dev/null
@@ -1,84 +0,0 @@
-// Structs contain data, but can also have logic. In this exercise, we have
-// defined the `Package` struct, and we want to test some logic attached to it.
-
-#[derive(Debug)]
-struct Package {
-    sender_country: String,
-    recipient_country: String,
-    weight_in_grams: u32,
-}
-
-impl Package {
-    fn new(sender_country: String, recipient_country: String, weight_in_grams: u32) -> Self {
-        if weight_in_grams < 10 {
-            // This isn't how you should handle errors in Rust, but we will
-            // learn about error handling later.
-            panic!("Can't ship a package with weight below 10 grams");
-        }
-
-        Self {
-            sender_country,
-            recipient_country,
-            weight_in_grams,
-        }
-    }
-
-    fn is_international(&self) -> bool {
-        self.sender_country != self.recipient_country
-    }
-
-    fn get_fees(&self, cents_per_gram: u32) -> u32 {
-        self.weight_in_grams * cents_per_gram
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    #[should_panic]
-    fn fail_creating_weightless_package() {
-        let sender_country = String::from("Spain");
-        let recipient_country = String::from("Austria");
-
-        Package::new(sender_country, recipient_country, 5);
-    }
-
-    #[test]
-    fn create_international_package() {
-        let sender_country = String::from("Spain");
-        let recipient_country = String::from("Russia");
-
-        let package = Package::new(sender_country, recipient_country, 1200);
-
-        assert!(package.is_international());
-    }
-
-    #[test]
-    fn create_local_package() {
-        let sender_country = String::from("Canada");
-        let recipient_country = sender_country.clone();
-
-        let package = Package::new(sender_country, recipient_country, 1200);
-
-        assert!(!package.is_international());
-    }
-
-    #[test]
-    fn calculate_transport_fees() {
-        let sender_country = String::from("Spain");
-        let recipient_country = String::from("Spain");
-
-        let cents_per_gram = 3;
-
-        let package = Package::new(sender_country, recipient_country, 1500);
-
-        assert_eq!(package.get_fees(cents_per_gram), 4500);
-        assert_eq!(package.get_fees(cents_per_gram * 2), 9000);
-    }
-}
diff --git a/rustlings/exercises/08_enums/README.md b/rustlings/exercises/08_enums/README.md
deleted file mode 100644
index b05cb42..0000000
--- a/rustlings/exercises/08_enums/README.md
+++ /dev/null
@@ -1,10 +0,0 @@
-# Enums
-
-Rust allows you to define types called "enums" which enumerate possible values.
-Enums are a feature in many languages, but their capabilities differ in each language. Rust's enums are most similar to algebraic data types in functional languages, such as F#, OCaml, and Haskell.
-Useful in combination with enums is Rust's "pattern matching" facility, which makes it easy to run different code for different values of an enumeration.
-
-## Further information
-
-- [Enums](https://doc.rust-lang.org/book/ch06-00-enums.html)
-- [Pattern syntax](https://doc.rust-lang.org/book/ch19-03-pattern-syntax.html)
diff --git a/rustlings/exercises/08_enums/enums1.rs b/rustlings/exercises/08_enums/enums1.rs
deleted file mode 100644
index 97a5cc0..0000000
--- a/rustlings/exercises/08_enums/enums1.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-#[derive(Debug)]
-enum Message {
-    Resize,
-    Move,
-    Echo,
-    ChangeColor,
-    Quit,
-}
-
-fn main() {
-    println!("{:?}", Message::Resize);
-    println!("{:?}", Message::Move);
-    println!("{:?}", Message::Echo);
-    println!("{:?}", Message::ChangeColor);
-    println!("{:?}", Message::Quit);
-}
diff --git a/rustlings/exercises/08_enums/enums2.rs b/rustlings/exercises/08_enums/enums2.rs
deleted file mode 100644
index 4a2d5ac..0000000
--- a/rustlings/exercises/08_enums/enums2.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-#[derive(Debug)]
-struct Point {
-    x: u64,
-    y: u64,
-}
-
-#[derive(Debug)]
-enum Message {
-    Resize {
-        width: u64,
-        height: u64,
-    },
-    Move(Point),
-    Echo(String),
-    ChangeColor(u8, u8, u8),
-    Quit,
-}
-
-impl Message {
-    fn call(&self) {
-        println!("{self:?}");
-    }
-}
-
-fn main() {
-    let messages = [
-        Message::Resize {
-            width: 10,
-            height: 30,
-        },
-        Message::Move(Point { x: 10, y: 15 }),
-        Message::Echo(String::from("hello world")),
-        Message::ChangeColor(200, 255, 255),
-        Message::Quit,
-    ];
-
-    for message in &messages {
-        message.call();
-    }
-}
diff --git a/rustlings/exercises/08_enums/enums3.rs b/rustlings/exercises/08_enums/enums3.rs
deleted file mode 100644
index bf01af3..0000000
--- a/rustlings/exercises/08_enums/enums3.rs
+++ /dev/null
@@ -1,93 +0,0 @@
-struct Point {
-    x: u64,
-    y: u64,
-}
-
-enum Message {
-    Resize { width: u64, height: u64 },
-    Move(Point),
-    Echo(String),
-    ChangeColor(u8, u8, u8),
-    Quit,
-}
-
-struct State {
-    width: u64,
-    height: u64,
-    position: Point,
-    message: String,
-    // RGB color composed of red, green and blue.
-    color: (u8, u8, u8),
-    quit: bool,
-}
-
-impl State {
-    fn resize(&mut self, width: u64, height: u64) {
-        self.width = width;
-        self.height = height;
-    }
-
-    fn move_position(&mut self, point: Point) {
-        self.position = point;
-    }
-
-    fn echo(&mut self, s: String) {
-        self.message = s;
-    }
-
-    fn change_color(&mut self, red: u8, green: u8, blue: u8) {
-        self.color = (red, green, blue);
-    }
-
-    fn quit(&mut self) {
-        self.quit = true;
-    }
-
-    fn process(&mut self, message: Message) {
-        match message {
-            Message::Resize { width, height } => self.resize(width, height),
-            Message::Move(point) => self.move_position(point),
-            Message::Echo(s) => self.echo(s),
-            Message::ChangeColor(red, green, blue) => self.change_color(red, green, blue),
-            Message::Quit => self.quit(),
-        }
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_match_message_call() {
-        let mut state = State {
-            width: 0,
-            height: 0,
-            position: Point { x: 0, y: 0 },
-            message: String::from("hello world"),
-            color: (0, 0, 0),
-            quit: false,
-        };
-
-        state.process(Message::Resize {
-            width: 10,
-            height: 30,
-        });
-        state.process(Message::Move(Point { x: 10, y: 15 }));
-        state.process(Message::Echo(String::from("Hello world!")));
-        state.process(Message::ChangeColor(255, 0, 255));
-        state.process(Message::Quit);
-
-        assert_eq!(state.width, 10);
-        assert_eq!(state.height, 30);
-        assert_eq!(state.position.x, 10);
-        assert_eq!(state.position.y, 15);
-        assert_eq!(state.message, "Hello world!");
-        assert_eq!(state.color, (255, 0, 255));
-        assert!(state.quit);
-    }
-}
diff --git a/rustlings/exercises/09_strings/README.md b/rustlings/exercises/09_strings/README.md
deleted file mode 100644
index fa2104c..0000000
--- a/rustlings/exercises/09_strings/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Strings
-
-Rust has two string types, a string slice (`&str`) and an owned string (`String`).
-We're not going to dictate when you should use which one, but we'll show you how
-to identify and create them, as well as use them.
-
-## Further information
-
-- [Strings](https://doc.rust-lang.org/book/ch08-02-strings.html)
diff --git a/rustlings/exercises/09_strings/strings1.rs b/rustlings/exercises/09_strings/strings1.rs
deleted file mode 100644
index 482e5de..0000000
--- a/rustlings/exercises/09_strings/strings1.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-fn current_favorite_color() -> String {
-    String::from("blue")
-}
-
-fn main() {
-    let answer = current_favorite_color();
-    println!("My current favorite color is {answer}");
-}
diff --git a/rustlings/exercises/09_strings/strings2.rs b/rustlings/exercises/09_strings/strings2.rs
deleted file mode 100644
index b03094f..0000000
--- a/rustlings/exercises/09_strings/strings2.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-fn is_a_color_word(attempt: &str) -> bool {
-    attempt == "green" || attempt == "blue" || attempt == "red"
-}
-
-fn main() {
-    let word = String::from("green"); // Don't change this line.
-
-    if is_a_color_word(&word) {
-        println!("That is a color word I know!");
-    } else {
-        println!("That is not a color word I know.");
-    }
-}
diff --git a/rustlings/exercises/09_strings/strings3.rs b/rustlings/exercises/09_strings/strings3.rs
deleted file mode 100644
index 3543ad5..0000000
--- a/rustlings/exercises/09_strings/strings3.rs
+++ /dev/null
@@ -1,46 +0,0 @@
-fn trim_me(input: &str) -> &str {
-    input.trim()
-}
-
-fn compose_me(input: &str) -> String {
-    String::from(input) + " world!"
-}
-
-fn replace_me(input: &str) -> String {
-    String::from(input).replace("cars", "balloons")
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn trim_a_string() {
-        assert_eq!(trim_me("Hello!     "), "Hello!");
-        assert_eq!(trim_me("  What's up!"), "What's up!");
-        assert_eq!(trim_me("   Hola!  "), "Hola!");
-        assert_eq!(trim_me("Hi!"), "Hi!");
-    }
-
-    #[test]
-    fn compose_a_string() {
-        assert_eq!(compose_me("Hello"), "Hello world!");
-        assert_eq!(compose_me("Goodbye"), "Goodbye world!");
-    }
-
-    #[test]
-    fn replace_a_string() {
-        assert_eq!(
-            replace_me("I think cars are cool"),
-            "I think balloons are cool",
-        );
-        assert_eq!(
-            replace_me("I love to look at cars"),
-            "I love to look at balloons",
-        );
-    }
-}
diff --git a/rustlings/exercises/09_strings/strings4.rs b/rustlings/exercises/09_strings/strings4.rs
deleted file mode 100644
index 3f7c5e7..0000000
--- a/rustlings/exercises/09_strings/strings4.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-// Calls of this function should be replaced with calls of `string_slice` or `string`.
-fn placeholder() {}
-
-fn string_slice(arg: &str) {
-    println!("{arg}");
-}
-
-fn string(arg: String) {
-    println!("{arg}");
-}
-
-// TODO: Here are a bunch of values - some are `String`, some are `&str`.
-// Your task is to replace `placeholder(…)` with either `string_slice(…)`
-// or `string(…)` depending on what you think each value is.
-fn main() {
-    string_slice("blue");
-
-    string("red".to_string());
-
-    string(String::from("hi"));
-
-    string("rust is fun!".to_owned());
-
-    string("nice weather".into());
-
-    string(format!("Interpolation {}", "Station"));
-
-    // WARNING: This is byte indexing, not character indexing.
-    // Character indexing can be done using `s.chars().nth(INDEX)`.
-    string_slice(&String::from("abc")[0..1]);
-
-    string_slice("  hello there ".trim());
-
-    string("Happy Monday!".replace("Mon", "Tues"));
-
-    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
-}
diff --git a/rustlings/exercises/10_modules/README.md b/rustlings/exercises/10_modules/README.md
deleted file mode 100644
index 3dc8a48..0000000
--- a/rustlings/exercises/10_modules/README.md
+++ /dev/null
@@ -1,7 +0,0 @@
-# Modules
-
-In this section we'll give you an introduction to Rust's module system.
-
-## Further information
-
-- [The Module System](https://doc.rust-lang.org/book/ch07-00-managing-growing-projects-with-packages-crates-and-modules.html)
diff --git a/rustlings/exercises/10_modules/modules1.rs b/rustlings/exercises/10_modules/modules1.rs
deleted file mode 100644
index 0d7c5a2..0000000
--- a/rustlings/exercises/10_modules/modules1.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-mod sausage_factory {
-    // Don't let anybody outside of this module see this!
-    fn get_secret_recipe() -> String {
-        String::from("Ginger")
-    }
-
-    pub fn make_sausage() {
-        get_secret_recipe();
-        println!("sausage!");
-    }
-}
-
-fn main() {
-    sausage_factory::make_sausage();
-}
diff --git a/rustlings/exercises/10_modules/modules2.rs b/rustlings/exercises/10_modules/modules2.rs
deleted file mode 100644
index 3cabbfd..0000000
--- a/rustlings/exercises/10_modules/modules2.rs
+++ /dev/null
@@ -1,26 +0,0 @@
-// You can bring module paths into scopes and provide new names for them with
-// the `use` and `as` keywords.
-
-mod delicious_snacks {
-    // TODO: Add the following two `use` statements after fixing them.
-    pub use self::fruits::PEAR as fruit;
-    pub use self::veggies::CUCUMBER as veggie;
-
-    mod fruits {
-        pub const PEAR: &str = "Pear";
-        pub const APPLE: &str = "Apple";
-    }
-
-    mod veggies {
-        pub const CUCUMBER: &str = "Cucumber";
-        pub const CARROT: &str = "Carrot";
-    }
-}
-
-fn main() {
-    println!(
-        "favorite snacks: {} and {}",
-        delicious_snacks::fruit,
-        delicious_snacks::veggie,
-    );
-}
diff --git a/rustlings/exercises/10_modules/modules3.rs b/rustlings/exercises/10_modules/modules3.rs
deleted file mode 100644
index 403b7ea..0000000
--- a/rustlings/exercises/10_modules/modules3.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// You can use the `use` keyword to bring module paths from modules from
-// anywhere and especially from the standard library into your scope.
-
-// TODO: Bring `SystemTime` and `UNIX_EPOCH` from the `std::time` module into
-// your scope. Bonus style points if you can do it with one line!
-use std::time::{SystemTime, UNIX_EPOCH};
-
-fn main() {
-    match SystemTime::now().duration_since(UNIX_EPOCH) {
-        Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()),
-        Err(_) => panic!("SystemTime before UNIX EPOCH!"),
-    }
-}
diff --git a/rustlings/exercises/11_hashmaps/README.md b/rustlings/exercises/11_hashmaps/README.md
deleted file mode 100644
index 80ec144..0000000
--- a/rustlings/exercises/11_hashmaps/README.md
+++ /dev/null
@@ -1,12 +0,0 @@
-# Hashmaps
-
-A *hash map* allows you to associate a value with a particular key.
-You may also know this by the names [*unordered map* in C++](https://en.cppreference.com/w/cpp/container/unordered_map),
-[*dictionary* in Python](https://docs.python.org/3/tutorial/datastructures.html#dictionaries) or an *associative array* in other languages.
-
-This is the other data structure that we've been talking about before, when
-talking about Vecs.
-
-## Further information
-
-- [Storing Keys with Associated Values in Hash Maps](https://doc.rust-lang.org/book/ch08-03-hash-maps.html)
diff --git a/rustlings/exercises/11_hashmaps/hashmaps1.rs b/rustlings/exercises/11_hashmaps/hashmaps1.rs
deleted file mode 100644
index a746b32..0000000
--- a/rustlings/exercises/11_hashmaps/hashmaps1.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-// 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 3 different
-// types of fruits (e.g. apple, banana, mango) in the basket and the total count
-// of all the fruits should be at least 5.
-
-use std::collections::HashMap;
-
-fn fruit_basket() -> HashMap<String, u32> {
-    // TODO: Declare the hash map.
-    let mut basket = HashMap::new();
-
-    // Two bananas are already given for you :)
-    basket.insert(String::from("banana"), 2);
-
-    // TODO: Put more fruits in your basket.
-    basket.insert(String::from("banana"), 1);
-    basket.insert(String::from("orange"), 140000);
-    basket.insert(String::from("strawberry"), 5);
-
-    basket
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[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);
-    }
-}
diff --git a/rustlings/exercises/11_hashmaps/hashmaps2.rs b/rustlings/exercises/11_hashmaps/hashmaps2.rs
deleted file mode 100644
index 482db7c..0000000
--- a/rustlings/exercises/11_hashmaps/hashmaps2.rs
+++ /dev/null
@@ -1,99 +0,0 @@
-// 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);
-        }
-    }
-}
diff --git a/rustlings/exercises/11_hashmaps/hashmaps3.rs b/rustlings/exercises/11_hashmaps/hashmaps3.rs
deleted file mode 100644
index 0fa4a6b..0000000
--- a/rustlings/exercises/11_hashmaps/hashmaps3.rs
+++ /dev/null
@@ -1,84 +0,0 @@
-// A list of scores (one per line) of a soccer match is given. Each line is of
-// the form "<team_1_name>,<team_2_name>,<team_1_goals>,<team_2_goals>"
-// Example: "England,France,4,2" (England scored 4 goals, France 2).
-//
-// You have to build a scores table containing the name of the team, the total
-// number of goals the team scored, and the total number of goals the team
-// conceded.
-
-use std::collections::HashMap;
-
-// A structure to store the goal details of a team.
-#[derive(Default)]
-struct TeamScores {
-    goals_scored: u8,
-    goals_conceded: u8,
-}
-
-fn build_scores_table(results: &str) -> HashMap<&str, TeamScores> {
-    // The name of the team is the key and its associated struct is the value.
-    let mut scores = HashMap::<&str, TeamScores>::new();
-
-    for line in results.lines() {
-        let mut split_iterator = line.split(',');
-        // NOTE: We use `unwrap` because we didn't deal with error handling yet.
-        let team_1_name = split_iterator.next().unwrap();
-        let team_2_name = split_iterator.next().unwrap();
-        let team_1_score: u8 = split_iterator.next().unwrap().parse().unwrap();
-        let team_2_score: u8 = split_iterator.next().unwrap().parse().unwrap();
-
-        // TODO: Populate the scores table with the extracted details.
-        // Keep in mind that goals scored by team 1 will be the number of goals
-        // conceded by team 2. Similarly, goals scored by team 2 will be the
-        // number of goals conceded by team 1.
-        let team_1 = scores.entry(team_1_name).or_default();
-        team_1.goals_scored += team_1_score;
-        team_1.goals_conceded += team_2_score;
-        let team_2 = scores.entry(team_2_name).or_default();
-        team_2.goals_scored += team_2_score;
-        team_2.goals_conceded += team_1_score;
-        
-    }
-
-    scores
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    const RESULTS: &str = "England,France,4,2
-France,Italy,3,1
-Poland,Spain,2,0
-Germany,England,2,1
-England,Spain,1,0";
-
-    #[test]
-    fn build_scores() {
-        let scores = build_scores_table(RESULTS);
-
-        assert!(["England", "France", "Germany", "Italy", "Poland", "Spain"]
-            .into_iter()
-            .all(|team_name| scores.contains_key(team_name)));
-    }
-
-    #[test]
-    fn validate_team_score_1() {
-        let scores = build_scores_table(RESULTS);
-        let team = scores.get("England").unwrap();
-        assert_eq!(team.goals_scored, 6);
-        assert_eq!(team.goals_conceded, 4);
-    }
-
-    #[test]
-    fn validate_team_score_2() {
-        let scores = build_scores_table(RESULTS);
-        let team = scores.get("Spain").unwrap();
-        assert_eq!(team.goals_scored, 0);
-        assert_eq!(team.goals_conceded, 3);
-    }
-}
diff --git a/rustlings/exercises/12_options/README.md b/rustlings/exercises/12_options/README.md
deleted file mode 100644
index 624572a..0000000
--- a/rustlings/exercises/12_options/README.md
+++ /dev/null
@@ -1,21 +0,0 @@
-# Options
-
-Type Option represents an optional value: every Option is either Some and contains a value, or None, and does not.
-Option types are very common in Rust code, as they have a number of uses:
-
-- Initial values
-- Return values for functions that are not defined over their entire input range (partial functions)
-- Return value for otherwise reporting simple errors, where None is returned on error
-- Optional struct fields
-- Struct fields that can be loaned or "taken"
-- Optional function arguments
-- Nullable pointers
-- Swapping things out of difficult situations
-
-## Further Information
-
-- [Option Enum Format](https://doc.rust-lang.org/book/ch10-01-syntax.html#in-enum-definitions)
-- [Option Module Documentation](https://doc.rust-lang.org/std/option/)
-- [Option Enum Documentation](https://doc.rust-lang.org/std/option/enum.Option.html)
-- [if let](https://doc.rust-lang.org/rust-by-example/flow_control/if_let.html)
-- [while let](https://doc.rust-lang.org/rust-by-example/flow_control/while_let.html)
diff --git a/rustlings/exercises/12_options/options1.rs b/rustlings/exercises/12_options/options1.rs
deleted file mode 100644
index be97952..0000000
--- a/rustlings/exercises/12_options/options1.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-// This function returns how much ice cream there is left in the fridge.
-// If it's before 22:00 (24-hour system), then 5 scoops are left. At 22:00,
-// someone eats it all, so no ice cream is left (value 0). Return `None` if
-// `hour_of_day` is higher than 23.
-fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
-    if hour_of_day >= 24 {
-        return None;
-    }
-    if hour_of_day >= 22 {
-        return Some(0);
-    }
-    Some(5)
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn raw_value() {
-        // TODO: Fix this test. How do you get the value contained in the
-        // Option?
-        let ice_creams = maybe_ice_cream(12).unwrap();
-
-        assert_eq!(ice_creams, 5); // Don't change this line.
-    }
-
-    #[test]
-    fn check_ice_cream() {
-        assert_eq!(maybe_ice_cream(0), Some(5));
-        assert_eq!(maybe_ice_cream(9), Some(5));
-        assert_eq!(maybe_ice_cream(18), Some(5));
-        assert_eq!(maybe_ice_cream(22), Some(0));
-        assert_eq!(maybe_ice_cream(23), Some(0));
-        assert_eq!(maybe_ice_cream(24), None);
-        assert_eq!(maybe_ice_cream(25), None);
-    }
-}
diff --git a/rustlings/exercises/12_options/options2.rs b/rustlings/exercises/12_options/options2.rs
deleted file mode 100644
index 1039d61..0000000
--- a/rustlings/exercises/12_options/options2.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn simple_option() {
-        let target = "rustlings";
-        let optional_target = Some(target);
-
-        // TODO: Make this an if-let statement whose value is `Some`.
-        if let Some(word) = optional_target {
-            assert_eq!(word, target);
-        }
-    }
-
-    #[test]
-    fn layered_option() {
-        let range = 10;
-        let mut optional_integers: Vec<Option<i8>> = vec![None];
-
-        for i in 1..=range {
-            optional_integers.push(Some(i));
-        }
-
-        let mut cursor = range;
-
-        // TODO: Make this a while-let statement. Remember that `Vec::pop()`
-        // adds another layer of `Option`. You can do nested pattern matching
-        // in if-let and while-let statements.
-        while let Some(Some(integer)) = optional_integers.pop() {
-            assert_eq!(integer, cursor);
-            cursor -= 1;
-        }
-
-        assert_eq!(cursor, 0);
-    }
-}
diff --git a/rustlings/exercises/12_options/options3.rs b/rustlings/exercises/12_options/options3.rs
deleted file mode 100644
index aecb7a5..0000000
--- a/rustlings/exercises/12_options/options3.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-#[derive(Debug)]
-struct Point {
-    x: i32,
-    y: i32,
-}
-
-fn main() {
-    let optional_point = Some(Point { x: 100, y: 200 });
-
-    // TODO: Fix the compiler error by adding something to this match statement.
-    match optional_point {
-        Some(ref p) => println!("Coordinates are {},{}", p.x, p.y),
-        _ => panic!("No match!"),
-    }
-
-    println!("{optional_point:?}"); // Don't change this line.
-}
diff --git a/rustlings/exercises/13_error_handling/README.md b/rustlings/exercises/13_error_handling/README.md
deleted file mode 100644
index 9b6674b..0000000
--- a/rustlings/exercises/13_error_handling/README.md
+++ /dev/null
@@ -1,12 +0,0 @@
-# Error handling
-
-Most errors aren't serious enough to require the program to stop entirely.
-Sometimes, when a function fails, it's for a reason that you can easily interpret and respond to.
-For example, if you try to open a file and that operation fails because the file doesn't exist, you might want to create the file instead of terminating the process.
-
-## Further information
-
-- [Error Handling](https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html)
-- [Generics](https://doc.rust-lang.org/book/ch10-01-syntax.html)
-- [Result](https://doc.rust-lang.org/rust-by-example/error/result.html)
-- [Boxing errors](https://doc.rust-lang.org/rust-by-example/error/multiple_error_types/boxing_errors.html)
diff --git a/rustlings/exercises/13_error_handling/errors1.rs b/rustlings/exercises/13_error_handling/errors1.rs
deleted file mode 100644
index b9b9bd5..0000000
--- a/rustlings/exercises/13_error_handling/errors1.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-// TODO: This function refuses to generate text to be printed on a nametag if
-// you pass it an empty string. It'd be nicer if it explained what the problem
-// was instead of just returning `None`. Thankfully, Rust has a similar
-// construct to `Option` that can be used to express error conditions. Change
-// the function signature and body to return `Result<String, String>` instead
-// of `Option<String>`.
-fn generate_nametag_text(name: String) -> Result<String, String> {
-    if name.is_empty() {
-        Err(String::from("Empty names aren't allowed"))
-    } else {
-        Ok(format!("Hi! My name is {name}"))
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn generates_nametag_text_for_a_nonempty_name() {
-        assert_eq!(
-            generate_nametag_text("Beyoncé".to_string()).as_deref(),
-            Ok("Hi! My name is Beyoncé"),
-        );
-    }
-
-    #[test]
-    fn explains_why_generating_nametag_text_fails() {
-        assert_eq!(
-            generate_nametag_text(String::new())
-                .as_ref()
-                .map_err(|e| e.as_str()),
-            Err("Empty names aren't allowed"),
-        );
-    }
-}
diff --git a/rustlings/exercises/13_error_handling/errors2.rs b/rustlings/exercises/13_error_handling/errors2.rs
deleted file mode 100644
index 3d850f7..0000000
--- a/rustlings/exercises/13_error_handling/errors2.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-// Say we're writing a game where you can buy items with tokens. All items cost
-// 5 tokens, and whenever you purchase items there is a processing fee of 1
-// token. A player of the game will type in how many items they want to buy, and
-// the `total_cost` function will calculate the total cost of the items. Since
-// the player typed in the quantity, we get it as a string. They might have
-// typed anything, not just numbers!
-//
-// Right now, this function isn't handling the error case at all. What we want
-// to do is: If we call the `total_cost` function on a string that is not a
-// number, that function will return a `ParseIntError`. In that case, we want to
-// immediately return that error from our function and not try to multiply and
-// add.
-//
-// There are at least two ways to implement this that are both correct. But one
-// is a lot shorter!
-
-use std::num::ParseIntError;
-
-fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
-    let processing_fee = 1;
-    let cost_per_item = 5;
-
-    // TODO: Handle the error case as described above.
-    let qty = item_quantity.parse::<i32>()?;
-
-    Ok(qty * cost_per_item + processing_fee)
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use std::num::IntErrorKind;
-
-    #[test]
-    fn item_quantity_is_a_valid_number() {
-        assert_eq!(total_cost("34"), Ok(171));
-    }
-
-    #[test]
-    fn item_quantity_is_an_invalid_number() {
-        assert_eq!(
-            total_cost("beep boop").unwrap_err().kind(),
-            &IntErrorKind::InvalidDigit,
-        );
-    }
-}
diff --git a/rustlings/exercises/13_error_handling/errors3.rs b/rustlings/exercises/13_error_handling/errors3.rs
deleted file mode 100644
index bf21bbc..0000000
--- a/rustlings/exercises/13_error_handling/errors3.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-// This is a program that is trying to use a completed version of the
-// `total_cost` function from the previous exercise. It's not working though!
-// Why not? What should we do to fix it?
-
-use std::num::ParseIntError;
-
-// Don't change this function.
-fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
-    let processing_fee = 1;
-    let cost_per_item = 5;
-    let qty = item_quantity.parse::<i32>()?;
-
-    Ok(qty * cost_per_item + processing_fee)
-}
-
-// TODO: Fix the compiler error by changing the signature and body of the
-// `main` function.
-fn main() -> Result<(), ParseIntError> {
-    let mut tokens = 100;
-    let pretend_user_input = "8";
-
-    // Don't change this line.
-    let cost = total_cost(pretend_user_input)?;
-
-    if cost > tokens {
-        println!("You can't afford that many!");
-    } else {
-        tokens -= cost;
-        println!("You now have {tokens} tokens.");
-    }
-
-    Ok(())
-}
diff --git a/rustlings/exercises/13_error_handling/errors4.rs b/rustlings/exercises/13_error_handling/errors4.rs
deleted file mode 100644
index e5f3d39..0000000
--- a/rustlings/exercises/13_error_handling/errors4.rs
+++ /dev/null
@@ -1,44 +0,0 @@
-#[derive(PartialEq, Debug)]
-enum CreationError {
-    Negative,
-    Zero,
-}
-
-#[derive(PartialEq, Debug)]
-struct PositiveNonzeroInteger(u64);
-
-impl PositiveNonzeroInteger {
-    fn new(value: i64) -> Result<Self, CreationError> {
-        // TODO: This function shouldn't always return an `Ok`.
-        // Read the tests below to clarify what should be returned.
-        if value < 0 {
-            return Err(CreationError::Negative);
-        }
-        if value == 0 {
-            return Err(CreationError::Zero);
-        }
-        Ok(Self(value as u64))
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_creation() {
-        assert_eq!(
-            PositiveNonzeroInteger::new(10),
-            Ok(PositiveNonzeroInteger(10)),
-        );
-        assert_eq!(
-            PositiveNonzeroInteger::new(-10),
-            Err(CreationError::Negative),
-        );
-        assert_eq!(PositiveNonzeroInteger::new(0), Err(CreationError::Zero));
-    }
-}
diff --git a/rustlings/exercises/13_error_handling/errors5.rs b/rustlings/exercises/13_error_handling/errors5.rs
deleted file mode 100644
index 405f0dc..0000000
--- a/rustlings/exercises/13_error_handling/errors5.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-// This exercise is an altered version of the `errors4` exercise. It uses some
-// concepts that we won't get to until later in the course, like `Box` and the
-// `From` trait. It's not important to understand them in detail right now, but
-// you can read ahead if you like. For now, think of the `Box<dyn ???>` type as
-// an "I want anything that does ???" type.
-//
-// In short, this particular use case for boxes is for when you want to own a
-// value and you care only that it is a type which implements a particular
-// trait. To do so, the `Box` is declared as of type `Box<dyn Trait>` where
-// `Trait` is the trait the compiler looks for on any value used in that
-// context. For this exercise, that context is the potential errors which
-// can be returned in a `Result`.
-
-use std::error::Error;
-use std::fmt;
-
-#[derive(PartialEq, Debug)]
-enum CreationError {
-    Negative,
-    Zero,
-}
-
-// This is required so that `CreationError` can implement `Error`.
-impl fmt::Display for CreationError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let description = match *self {
-            CreationError::Negative => "number is negative",
-            CreationError::Zero => "number is zero",
-        };
-        f.write_str(description)
-    }
-}
-
-impl Error for CreationError {}
-
-#[derive(PartialEq, Debug)]
-struct PositiveNonzeroInteger(u64);
-
-impl PositiveNonzeroInteger {
-    fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        match value {
-            x if x < 0 => Err(CreationError::Negative),
-            0 => Err(CreationError::Zero),
-            x => Ok(PositiveNonzeroInteger(x as u64)),
-        }
-    }
-}
-
-// TODO: Add the correct return type `Result<(), Box<dyn ???>>`. What can we
-// use to describe both errors? Is there a trait which both errors implement?
-fn main() -> Result<(), Box<dyn Error>> {
-    let pretend_user_input = "42";
-    let x: i64 = pretend_user_input.parse()?;
-    println!("output={:?}", PositiveNonzeroInteger::new(x)?);
-    Ok(())
-}
diff --git a/rustlings/exercises/13_error_handling/errors6.rs b/rustlings/exercises/13_error_handling/errors6.rs
deleted file mode 100644
index 353b50b..0000000
--- a/rustlings/exercises/13_error_handling/errors6.rs
+++ /dev/null
@@ -1,91 +0,0 @@
-// Using catch-all error types like `Box<dyn Error>` isn't recommended for
-// library code where callers might want to make decisions based on the error
-// content instead of printing it out or propagating it further. Here, we define
-// a custom error type to make it possible for callers to decide what to do next
-// when our function returns an error.
-
-use std::num::ParseIntError;
-
-#[derive(PartialEq, Debug)]
-enum CreationError {
-    Negative,
-    Zero,
-}
-
-// A custom error type that we will be using in `PositiveNonzeroInteger::parse`.
-#[derive(PartialEq, Debug)]
-enum ParsePosNonzeroError {
-    Creation(CreationError),
-    ParseInt(ParseIntError),
-}
-
-impl ParsePosNonzeroError {
-    fn from_creation(err: CreationError) -> Self {
-        Self::Creation(err)
-    }
-
-    // TODO: Add another error conversion function here.
-    fn from_parse_int(err: ParseIntError) -> Self {
-        Self::ParseInt(err)
-    }
-}
-
-#[derive(PartialEq, Debug)]
-struct PositiveNonzeroInteger(u64);
-
-impl PositiveNonzeroInteger {
-    fn new(value: i64) -> Result<Self, CreationError> {
-        match value {
-            x if x < 0 => Err(CreationError::Negative),
-            0 => Err(CreationError::Zero),
-            x => Ok(Self(x as u64)),
-        }
-    }
-
-    fn parse(s: &str) -> Result<Self, ParsePosNonzeroError> {
-        // TODO: change this to return an appropriate error instead of panicking
-        // when `parse()` returns an error.
-        let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parse_int)?;
-        Self::new(x).map_err(ParsePosNonzeroError::from_creation)
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn test_parse_error() {
-        assert!(matches!(
-            PositiveNonzeroInteger::parse("not a number"),
-            Err(ParsePosNonzeroError::ParseInt(_)),
-        ));
-    }
-
-    #[test]
-    fn test_negative() {
-        assert_eq!(
-            PositiveNonzeroInteger::parse("-555"),
-            Err(ParsePosNonzeroError::Creation(CreationError::Negative)),
-        );
-    }
-
-    #[test]
-    fn test_zero() {
-        assert_eq!(
-            PositiveNonzeroInteger::parse("0"),
-            Err(ParsePosNonzeroError::Creation(CreationError::Zero)),
-        );
-    }
-
-    #[test]
-    fn test_positive() {
-        let x = PositiveNonzeroInteger::new(42).unwrap();
-        assert_eq!(x.0, 42);
-        assert_eq!(PositiveNonzeroInteger::parse("42"), Ok(x));
-    }
-}
diff --git a/rustlings/exercises/14_generics/README.md b/rustlings/exercises/14_generics/README.md
deleted file mode 100644
index 0c8c8cb..0000000
--- a/rustlings/exercises/14_generics/README.md
+++ /dev/null
@@ -1,11 +0,0 @@
-# Generics
-
-Generics is the topic of generalizing types and functionalities to broader cases.
-This is extremely useful for reducing code duplication in many ways, but can call for some rather involved syntax.
-Namely, being generic requires taking great care to specify over which types a generic type is actually considered valid.
-The simplest and most common use of generics is for type parameters.
-
-## Further information
-
-- [Generic Data Types](https://doc.rust-lang.org/book/ch10-01-syntax.html)
-- [Bounds](https://doc.rust-lang.org/rust-by-example/generics/bounds.html)
diff --git a/rustlings/exercises/14_generics/generics1.rs b/rustlings/exercises/14_generics/generics1.rs
deleted file mode 100644
index 7e5571f..0000000
--- a/rustlings/exercises/14_generics/generics1.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// `Vec<T>` is generic over the type `T`. In most cases, the compiler is able to
-// infer `T`, for example after pushing a value with a concrete type to the vector.
-// But in this exercise, the compiler needs some help through a type annotation.
-
-fn main() {
-    // TODO: Fix the compiler error by annotating the type of the vector
-    // `Vec<T>`. Choose `T` as some integer type that can be created from
-    // `u8` and `i8`.
-    let mut numbers: Vec<i32> = Vec::new();
-
-    // Don't change the lines below.
-    let n1: u8 = 42;
-    numbers.push(n1.into());
-    let n2: i8 = -1;
-    numbers.push(n2.into());
-
-    println!("{numbers:?}");
-}
diff --git a/rustlings/exercises/14_generics/generics2.rs b/rustlings/exercises/14_generics/generics2.rs
deleted file mode 100644
index ba77625..0000000
--- a/rustlings/exercises/14_generics/generics2.rs
+++ /dev/null
@@ -1,31 +0,0 @@
-// This powerful wrapper provides the ability to store a positive integer value.
-// TODO: Rewrite it using a generic so that it supports wrapping ANY type.
-struct Wrapper<T> {
-    value: T,
-}
-
-// TODO: Adapt the struct's implementation to be generic over the wrapped value.
-impl<T> Wrapper<T> {
-    fn new(value: T) -> Self {
-        Wrapper { value }
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn store_u32_in_wrapper() {
-        assert_eq!(Wrapper::new(42).value, 42);
-    }
-
-    #[test]
-    fn store_str_in_wrapper() {
-        assert_eq!(Wrapper::new("Foo").value, "Foo");
-    }
-}
diff --git a/rustlings/exercises/15_traits/README.md b/rustlings/exercises/15_traits/README.md
deleted file mode 100644
index ac87c64..0000000
--- a/rustlings/exercises/15_traits/README.md
+++ /dev/null
@@ -1,19 +0,0 @@
-# Traits
-
-A trait is a collection of methods.
-
-Data types can implement traits. To do so, the methods making up the trait are defined for the data type. For example, the `String` data type implements the `From<&str>` trait. This allows a user to write `String::from("hello")`.
-
-In this way, traits are somewhat similar to Java interfaces and C++ abstract classes.
-
-Some additional common Rust traits include:
-
-- `Clone` (the `clone` method)
-- `Display` (which allows formatted display via `{}`)
-- `Debug` (which allows formatted display via `{:?}`)
-
-Because traits indicate shared behavior between data types, they are useful when writing generics.
-
-## Further information
-
-- [Traits](https://doc.rust-lang.org/book/ch10-02-traits.html)
diff --git a/rustlings/exercises/15_traits/traits1.rs b/rustlings/exercises/15_traits/traits1.rs
deleted file mode 100644
index fad6a50..0000000
--- a/rustlings/exercises/15_traits/traits1.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-// The trait `AppendBar` has only one function which appends "Bar" to any object
-// implementing this trait.
-trait AppendBar {
-    fn append_bar(self) -> Self;
-}
-
-impl AppendBar for String {
-    // TODO: Implement `AppendBar` for the type `String`.
-    fn append_bar(self) -> Self {
-        self + "Bar"
-    }
-}
-
-fn main() {
-    let s = String::from("Foo");
-    let s = s.append_bar();
-    println!("s: {s}");
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn is_foo_bar() {
-        assert_eq!(String::from("Foo").append_bar(), "FooBar");
-    }
-
-    #[test]
-    fn is_bar_bar() {
-        assert_eq!(String::from("").append_bar().append_bar(), "BarBar");
-    }
-}
diff --git a/rustlings/exercises/15_traits/traits2.rs b/rustlings/exercises/15_traits/traits2.rs
deleted file mode 100644
index 5dfc36d..0000000
--- a/rustlings/exercises/15_traits/traits2.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-trait AppendBar {
-    fn append_bar(self) -> Self;
-}
-
-// TODO: Implement the trait `AppendBar` for a vector of strings.
-// `append_bar` should push the string "Bar" into the vector.
-
-impl AppendBar for Vec<String> {
-    fn append_bar(self) -> Self {
-        let mut s = self.clone();
-        s.push(String::from("Bar"));
-        s
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn is_vec_pop_eq_bar() {
-        let mut foo = vec![String::from("Foo")].append_bar();
-        assert_eq!(foo.pop().unwrap(), "Bar");
-        assert_eq!(foo.pop().unwrap(), "Foo");
-    }
-}
diff --git a/rustlings/exercises/15_traits/traits3.rs b/rustlings/exercises/15_traits/traits3.rs
deleted file mode 100644
index 144ac0a..0000000
--- a/rustlings/exercises/15_traits/traits3.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-trait Licensed {
-    // TODO: Add a default implementation for `licensing_info` so that
-    // implementors like the two structs below can share that default behavior
-    // without repeating the function.
-    // The default license information should be the string "Default license".
-    fn licensing_info(&self) -> String {
-        String::from("Default license")
-    }
-}
-
-struct SomeSoftware {
-    version_number: i32,
-}
-
-struct OtherSoftware {
-    version_number: String,
-}
-
-impl Licensed for SomeSoftware {} // Don't edit this line.
-impl Licensed for OtherSoftware {} // Don't edit this line.
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn is_licensing_info_the_same() {
-        let licensing_info = "Default license";
-        let some_software = SomeSoftware { version_number: 1 };
-        let other_software = OtherSoftware {
-            version_number: "v2.0.0".to_string(),
-        };
-        assert_eq!(some_software.licensing_info(), licensing_info);
-        assert_eq!(other_software.licensing_info(), licensing_info);
-    }
-}
diff --git a/rustlings/exercises/15_traits/traits4.rs b/rustlings/exercises/15_traits/traits4.rs
deleted file mode 100644
index b23dcdd..0000000
--- a/rustlings/exercises/15_traits/traits4.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-trait Licensed {
-    fn licensing_info(&self) -> String {
-        "Default license".to_string()
-    }
-}
-
-struct SomeSoftware;
-struct OtherSoftware;
-
-impl Licensed for SomeSoftware {}
-impl Licensed for OtherSoftware {}
-
-// TODO: Fix the compiler error by only changing the signature of this function.
-fn compare_license_types(software1: impl Licensed, software2: impl Licensed) -> bool {
-    software1.licensing_info() == software2.licensing_info()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn compare_license_information() {
-        assert!(compare_license_types(SomeSoftware, OtherSoftware));
-    }
-
-    #[test]
-    fn compare_license_information_backwards() {
-        assert!(compare_license_types(OtherSoftware, SomeSoftware));
-    }
-}
diff --git a/rustlings/exercises/15_traits/traits5.rs b/rustlings/exercises/15_traits/traits5.rs
deleted file mode 100644
index 6548014..0000000
--- a/rustlings/exercises/15_traits/traits5.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-trait SomeTrait {
-    fn some_function(&self) -> bool {
-        true
-    }
-}
-
-trait OtherTrait {
-    fn other_function(&self) -> bool {
-        true
-    }
-}
-
-struct SomeStruct;
-impl SomeTrait for SomeStruct {}
-impl OtherTrait for SomeStruct {}
-
-struct OtherStruct;
-impl SomeTrait for OtherStruct {}
-impl OtherTrait for OtherStruct {}
-
-// TODO: Fix the compiler error by only changing the signature of this function.
-fn some_func<T : SomeTrait + OtherTrait>(item: T) -> bool {
-    item.some_function() && item.other_function()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_some_func() {
-        assert!(some_func(SomeStruct));
-        assert!(some_func(OtherStruct));
-    }
-}
diff --git a/rustlings/exercises/16_lifetimes/README.md b/rustlings/exercises/16_lifetimes/README.md
deleted file mode 100644
index 91373f7..0000000
--- a/rustlings/exercises/16_lifetimes/README.md
+++ /dev/null
@@ -1,22 +0,0 @@
-# Lifetimes
-
-Lifetimes tell the compiler how to check whether references live long
-enough to be valid in any given situation. For example lifetimes say
-"make sure parameter 'a' lives as long as parameter 'b' so that the return
-value is valid".
-
-They are only necessary on borrows, i.e. references,
-since copied parameters or moves are owned in their scope and cannot
-be referenced outside. Lifetimes mean that calling code of e.g. functions
-can be checked to make sure their arguments are valid. Lifetimes are
-restrictive of their callers.
-
-If you'd like to learn more about lifetime annotations, the
-[lifetimekata](https://tfpk.github.io/lifetimekata/) project
-has a similar style of exercises to Rustlings, but is all about
-learning to write lifetime annotations.
-
-## Further information
-
-- [Lifetimes (in Rust By Example)](https://doc.rust-lang.org/stable/rust-by-example/scope/lifetime.html)
-- [Validating References with Lifetimes](https://doc.rust-lang.org/book/ch10-03-lifetime-syntax.html)
diff --git a/rustlings/exercises/16_lifetimes/lifetimes1.rs b/rustlings/exercises/16_lifetimes/lifetimes1.rs
deleted file mode 100644
index 683bd75..0000000
--- a/rustlings/exercises/16_lifetimes/lifetimes1.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-// The Rust compiler needs to know how to check whether supplied references are
-// valid, so that it can let the programmer know if a reference is at risk of
-// going out of scope before it is used. Remember, references are borrows and do
-// not own their own data. What if their owner goes out of scope?
-
-// TODO: Fix the compiler error by updating the function signature.
-fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
-    if x.len() > y.len() {
-        x
-    } else {
-        y
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_longest() {
-        assert_eq!(longest("abcd", "123"), "abcd");
-        assert_eq!(longest("abc", "1234"), "1234");
-    }
-}
diff --git a/rustlings/exercises/16_lifetimes/lifetimes2.rs b/rustlings/exercises/16_lifetimes/lifetimes2.rs
deleted file mode 100644
index ebbc99c..0000000
--- a/rustlings/exercises/16_lifetimes/lifetimes2.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-// Don't change this function.
-fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
-    if x.len() > y.len() {
-        x
-    } else {
-        y
-    }
-}
-
-fn main() {
-    // TODO: Fix the compiler error by moving one line.
-
-    let string1 = String::from("long string is long");
-    let string2 = String::from("xyz");
-    let result;
-    {
-        result = longest(&string1, &string2);
-    }
-    println!("The longest string is '{result}'");
-}
diff --git a/rustlings/exercises/16_lifetimes/lifetimes3.rs b/rustlings/exercises/16_lifetimes/lifetimes3.rs
deleted file mode 100644
index 91e3922..0000000
--- a/rustlings/exercises/16_lifetimes/lifetimes3.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// Lifetimes are also needed when structs hold references.
-
-// TODO: Fix the compiler errors about the struct.
-struct Book<'a> {
-    author: &'a str,
-    title: &'a str,
-}
-
-fn main() {
-    let book = Book {
-        author: "George Orwell",
-        title: "1984",
-    };
-
-    println!("{} by {}", book.title, book.author);
-}
diff --git a/rustlings/exercises/17_tests/README.md b/rustlings/exercises/17_tests/README.md
deleted file mode 100644
index 27c6818..0000000
--- a/rustlings/exercises/17_tests/README.md
+++ /dev/null
@@ -1,7 +0,0 @@
-# Tests
-
-Going out of order from the book to cover tests -- many of the following exercises will ask you to make tests pass!
-
-## Further information
-
-- [Writing Tests](https://doc.rust-lang.org/book/ch11-01-writing-tests.html)
diff --git a/rustlings/exercises/17_tests/tests1.rs b/rustlings/exercises/17_tests/tests1.rs
deleted file mode 100644
index 7fd7e10..0000000
--- a/rustlings/exercises/17_tests/tests1.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-// Tests are important to ensure that your code does what you think it should
-// do.
-
-fn is_even(n: i64) -> bool {
-    n % 2 == 0
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    // TODO: Import `is_even`. You can use a wildcard to import everything in
-    // the outer module.
-    use super::*;
-
-    #[test]
-    fn you_can_assert() {
-        // TODO: Test the function `is_even` with some values.
-        assert!(is_even(2));
-        assert!(!is_even(3));
-    }
-}
diff --git a/rustlings/exercises/17_tests/tests2.rs b/rustlings/exercises/17_tests/tests2.rs
deleted file mode 100644
index 16bf0fa..0000000
--- a/rustlings/exercises/17_tests/tests2.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-// Calculates the power of 2 using a bit shift.
-// `1 << n` is equivalent to "2 to the power of n".
-fn power_of_2(n: u8) -> u64 {
-    1 << n
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn you_can_assert_eq() {
-        // TODO: Test the function `power_of_2` with some values.
-        assert_eq!(power_of_2(1), 2);
-        assert_eq!(power_of_2(2), 4);
-        assert_eq!(power_of_2(3), 8);
-        assert_eq!(power_of_2(4), 16);
-    }
-}
diff --git a/rustlings/exercises/17_tests/tests3.rs b/rustlings/exercises/17_tests/tests3.rs
deleted file mode 100644
index 085bb62..0000000
--- a/rustlings/exercises/17_tests/tests3.rs
+++ /dev/null
@@ -1,51 +0,0 @@
-struct Rectangle {
-    width: i32,
-    height: i32,
-}
-
-impl Rectangle {
-    // Don't change this function.
-    fn new(width: i32, height: i32) -> Self {
-        if width <= 0 || height <= 0 {
-            // Returning a `Result` would be better here. But we want to learn
-            // how to test functions that can panic.
-            panic!("Rectangle width and height must be positive");
-        }
-
-        Rectangle { width, height }
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn correct_width_and_height() {
-        // TODO: This test should check if the rectangle has the size that we
-        // pass to its constructor.
-        let rect = Rectangle::new(10, 20);
-        assert_eq!(rect.width, 10); // Check width
-        assert_eq!(rect.height, 20); // Check height
-    }
-
-    // TODO: This test should check if the program panics when we try to create
-    // a rectangle with negative width.
-    #[test]
-    #[should_panic]
-    fn negative_width() {
-        let _rect = Rectangle::new(-10, 10);
-    }
-
-    // TODO: This test should check if the program panics when we try to create
-    // a rectangle with negative height.
-    #[test]
-    #[should_panic]
-    fn negative_height() {
-        let _rect = Rectangle::new(10, -10);
-    }
-}
diff --git a/rustlings/exercises/18_iterators/README.md b/rustlings/exercises/18_iterators/README.md
deleted file mode 100644
index 0e8b671..0000000
--- a/rustlings/exercises/18_iterators/README.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Iterators
-
-This section will teach you about Iterators.
-
-## Further information
-
-- [Iterator](https://doc.rust-lang.org/book/ch13-02-iterators.html)
-- [Iterator documentation](https://doc.rust-lang.org/stable/std/iter/)
diff --git a/rustlings/exercises/18_iterators/iterators1.rs b/rustlings/exercises/18_iterators/iterators1.rs
deleted file mode 100644
index 71d8112..0000000
--- a/rustlings/exercises/18_iterators/iterators1.rs
+++ /dev/null
@@ -1,25 +0,0 @@
-// When performing operations on elements within a collection, iterators are
-// essential. This module helps you get familiar with the structure of using an
-// iterator and how to go through elements within an iterable collection.
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn iterators() {
-        let my_fav_fruits = ["banana", "custard apple", "avocado", "peach", "raspberry"];
-
-        // TODO: Create an iterator over the array.
-        let mut fav_fruits_iterator = my_fav_fruits.iter();
-
-        assert_eq!(fav_fruits_iterator.next(), Some(&"banana"));
-        assert_eq!(fav_fruits_iterator.next(), Some(&"custard apple")); // TODO: Replace `todo!()`
-        assert_eq!(fav_fruits_iterator.next(), Some(&"avocado"));
-        assert_eq!(fav_fruits_iterator.next(), Some(&"peach")); // TODO: Replace `todo!()`
-        assert_eq!(fav_fruits_iterator.next(), Some(&"raspberry"));
-        assert_eq!(fav_fruits_iterator.next(), None); // TODO: Replace `todo!()`
-    }
-}
diff --git a/rustlings/exercises/18_iterators/iterators2.rs b/rustlings/exercises/18_iterators/iterators2.rs
deleted file mode 100644
index c827529..0000000
--- a/rustlings/exercises/18_iterators/iterators2.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-// In this exercise, you'll learn some of the unique advantages that iterators
-// can offer.
-
-// TODO: Complete the `capitalize_first` function.
-// "hello" -> "Hello"
-fn capitalize_first(input: &str) -> String {
-    let mut chars = input.chars();
-    match chars.next() {
-        None => String::new(),
-        Some(first) => first.to_uppercase().to_string() + &input[1..],
-    }
-}
-
-// TODO: Apply the `capitalize_first` function to a slice of string slices.
-// Return a vector of strings.
-// ["hello", "world"] -> ["Hello", "World"]
-fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
-    let mut v = Vec::new();
-    for word in words {
-        if !word.trim().is_empty() {
-            v.push(capitalize_first(word));
-        }
-    }
-    v
-}
-
-// TODO: Apply the `capitalize_first` function again to a slice of string
-// slices. Return a single string.
-// ["hello", " ", "world"] -> "Hello World"
-fn capitalize_words_string(words: &[&str]) -> String {
-    capitalize_words_vector(words).join(" ")
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_success() {
-        assert_eq!(capitalize_first("hello"), "Hello");
-    }
-
-    #[test]
-    fn test_empty() {
-        assert_eq!(capitalize_first(""), "");
-    }
-
-    #[test]
-    fn test_iterate_string_vec() {
-        let words = vec!["hello", "world"];
-        assert_eq!(capitalize_words_vector(&words), ["Hello", "World"]);
-    }
-
-    #[test]
-    fn test_iterate_into_string() {
-        let words = vec!["hello", " ", "world"];
-        assert_eq!(capitalize_words_string(&words), "Hello World");
-    }
-}
diff --git a/rustlings/exercises/18_iterators/iterators3.rs b/rustlings/exercises/18_iterators/iterators3.rs
deleted file mode 100644
index 919739b..0000000
--- a/rustlings/exercises/18_iterators/iterators3.rs
+++ /dev/null
@@ -1,84 +0,0 @@
-#[derive(Debug, PartialEq, Eq)]
-enum DivisionError {
-    // Example: 42 / 0
-    DivideByZero,
-    // Only case for `i64`: `i64::MIN / -1` because the result is `i64::MAX + 1`
-    IntegerOverflow,
-    // Example: 5 / 2 = 2.5
-    NotDivisible,
-}
-
-// TODO: Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
-// Otherwise, return a suitable error.
-fn divide(a: i64, b: i64) -> Result<i64, DivisionError> {
-    if b == 0 {
-        return Err(DivisionError::DivideByZero);
-    }
-    if a == i64::MIN && b == -1 {
-        return Err(DivisionError::IntegerOverflow);
-    }
-    if a % b != 0 {
-        return Err(DivisionError::NotDivisible);
-    }
-    Ok(a / b)
-}
-
-// TODO: Add the correct return type and complete the function body.
-// Desired output: `Ok([1, 11, 1426, 3])`
-fn result_with_list() -> Result<Vec<i64>, DivisionError> {
-    let numbers = [27, 297, 38502, 81];
-    numbers.into_iter().map(|n| divide(n, 27)).collect()
-}
-
-// TODO: Add the correct return type and complete the function body.
-// Desired output: `[Ok(1), Ok(11), Ok(1426), Ok(3)]`
-fn list_of_results() -> Vec<Result<i64, DivisionError>> {
-    let numbers = [27, 297, 38502, 81];
-    numbers.into_iter().map(|n| divide(n, 27)).collect()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_success() {
-        assert_eq!(divide(81, 9), Ok(9));
-        assert_eq!(divide(81, -1), Ok(-81));
-        assert_eq!(divide(i64::MIN, i64::MIN), Ok(1));
-    }
-
-    #[test]
-    fn test_divide_by_0() {
-        assert_eq!(divide(81, 0), Err(DivisionError::DivideByZero));
-    }
-
-    #[test]
-    fn test_integer_overflow() {
-        assert_eq!(divide(i64::MIN, -1), Err(DivisionError::IntegerOverflow));
-    }
-
-    #[test]
-    fn test_not_divisible() {
-        assert_eq!(divide(81, 6), Err(DivisionError::NotDivisible));
-    }
-
-    #[test]
-    fn test_divide_0_by_something() {
-        assert_eq!(divide(0, 81), Ok(0));
-    }
-
-    #[test]
-    fn test_result_with_list() {
-        assert_eq!(result_with_list().unwrap(), [1, 11, 1426, 3]);
-    }
-
-    #[test]
-    fn test_list_of_results() {
-        assert_eq!(list_of_results(), [Ok(1), Ok(11), Ok(1426), Ok(3)]);
-    }
-}
diff --git a/rustlings/exercises/18_iterators/iterators4.rs b/rustlings/exercises/18_iterators/iterators4.rs
deleted file mode 100644
index f153786..0000000
--- a/rustlings/exercises/18_iterators/iterators4.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-fn factorial(num: u64) -> u64 {
-    // TODO: Complete this function to return the factorial of `num` which is
-    // defined as `1 * 2 * 3 * … * num`.
-    // https://en.wikipedia.org/wiki/Factorial
-    //
-    // Do not use:
-    // - early returns (using the `return` keyword explicitly)
-    // Try not to use:
-    // - imperative style loops (for/while)
-    // - additional variables
-    // For an extra challenge, don't use:
-    // - recursion
-    (1..=num).reduce(|a, b| a * b).unwrap_or(1)
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn factorial_of_0() {
-        assert_eq!(factorial(0), 1);
-    }
-
-    #[test]
-    fn factorial_of_1() {
-        assert_eq!(factorial(1), 1);
-    }
-    #[test]
-    fn factorial_of_2() {
-        assert_eq!(factorial(2), 2);
-    }
-
-    #[test]
-    fn factorial_of_4() {
-        assert_eq!(factorial(4), 24);
-    }
-}
diff --git a/rustlings/exercises/18_iterators/iterators5.rs b/rustlings/exercises/18_iterators/iterators5.rs
deleted file mode 100644
index 74f1c74..0000000
--- a/rustlings/exercises/18_iterators/iterators5.rs
+++ /dev/null
@@ -1,155 +0,0 @@
-// Let's define a simple model to track Rustlings' exercise progress. Progress
-// will be modelled using a hash map. The name of the exercise is the key and
-// the progress is the value. Two counting functions were created to count the
-// number of exercises with a given progress. Recreate this counting
-// functionality using iterators. Try to not use imperative loops (for/while).
-
-use std::collections::HashMap;
-
-#[derive(Clone, Copy, PartialEq, Eq)]
-enum Progress {
-    None,
-    Some,
-    Complete,
-}
-
-fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
-    let mut count = 0;
-    for val in map.values() {
-        if *val == value {
-            count += 1;
-        }
-    }
-    count
-}
-
-// TODO: Implement the functionality of `count_for` but with an iterator instead
-// of a `for` loop.
-fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
-    map.values().filter(|&&x| x == value).count()
-    // `map` is a hash map with `String` keys and `Progress` values.
-    // map = { "variables1": Complete, "from_str": None, … }
-}
-
-fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
-    let mut count = 0;
-    for map in collection {
-        for val in map.values() {
-            if *val == value {
-                count += 1;
-            }
-        }
-    }
-    count
-}
-
-// TODO: Implement the functionality of `count_collection_for` but with an
-// iterator instead of a `for` loop.
-fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
-    collection.iter().map(|m| count_iterator(m, value)).sum()
-    // `collection` is a slice of hash maps.
-    // collection = [{ "variables1": Complete, "from_str": None, … },
-    //               { "variables2": Complete, … }, … ]
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn get_map() -> HashMap<String, Progress> {
-        use Progress::*;
-
-        let mut map = HashMap::new();
-        map.insert(String::from("variables1"), Complete);
-        map.insert(String::from("functions1"), Complete);
-        map.insert(String::from("hashmap1"), Complete);
-        map.insert(String::from("arc1"), Some);
-        map.insert(String::from("as_ref_mut"), None);
-        map.insert(String::from("from_str"), None);
-
-        map
-    }
-
-    fn get_vec_map() -> Vec<HashMap<String, Progress>> {
-        use Progress::*;
-
-        let map = get_map();
-
-        let mut other = HashMap::new();
-        other.insert(String::from("variables2"), Complete);
-        other.insert(String::from("functions2"), Complete);
-        other.insert(String::from("if1"), Complete);
-        other.insert(String::from("from_into"), None);
-        other.insert(String::from("try_from_into"), None);
-
-        vec![map, other]
-    }
-
-    #[test]
-    fn count_complete() {
-        let map = get_map();
-        assert_eq!(count_iterator(&map, Progress::Complete), 3);
-    }
-
-    #[test]
-    fn count_some() {
-        let map = get_map();
-        assert_eq!(count_iterator(&map, Progress::Some), 1);
-    }
-
-    #[test]
-    fn count_none() {
-        let map = get_map();
-        assert_eq!(count_iterator(&map, Progress::None), 2);
-    }
-
-    #[test]
-    fn count_complete_equals_for() {
-        let map = get_map();
-        let progress_states = [Progress::Complete, Progress::Some, Progress::None];
-        for progress_state in progress_states {
-            assert_eq!(
-                count_for(&map, progress_state),
-                count_iterator(&map, progress_state),
-            );
-        }
-    }
-
-    #[test]
-    fn count_collection_complete() {
-        let collection = get_vec_map();
-        assert_eq!(
-            count_collection_iterator(&collection, Progress::Complete),
-            6,
-        );
-    }
-
-    #[test]
-    fn count_collection_some() {
-        let collection = get_vec_map();
-        assert_eq!(count_collection_iterator(&collection, Progress::Some), 1);
-    }
-
-    #[test]
-    fn count_collection_none() {
-        let collection = get_vec_map();
-        assert_eq!(count_collection_iterator(&collection, Progress::None), 4);
-    }
-
-    #[test]
-    fn count_collection_equals_for() {
-        let collection = get_vec_map();
-        let progress_states = [Progress::Complete, Progress::Some, Progress::None];
-
-        for progress_state in progress_states {
-            assert_eq!(
-                count_collection_for(&collection, progress_state),
-                count_collection_iterator(&collection, progress_state),
-            );
-        }
-    }
-}
diff --git a/rustlings/exercises/19_smart_pointers/README.md b/rustlings/exercises/19_smart_pointers/README.md
deleted file mode 100644
index d56d2b6..0000000
--- a/rustlings/exercises/19_smart_pointers/README.md
+++ /dev/null
@@ -1,12 +0,0 @@
-# Smart Pointers
-
-In Rust, smart pointers are variables that contain an address in memory and reference some other data, but they also have additional metadata and capabilities.
-Smart pointers in Rust often own the data they point to, while references only borrow data.
-
-## Further Information
-
-- [Smart Pointers](https://doc.rust-lang.org/book/ch15-00-smart-pointers.html)
-- [Using Box to Point to Data on the Heap](https://doc.rust-lang.org/book/ch15-01-box.html)
-- [Rc\<T\>, the Reference Counted Smart Pointer](https://doc.rust-lang.org/book/ch15-04-rc.html)
-- [Shared-State Concurrency](https://doc.rust-lang.org/book/ch16-03-shared-state.html)
-- [Cow Documentation](https://doc.rust-lang.org/std/borrow/enum.Cow.html)
diff --git a/rustlings/exercises/19_smart_pointers/arc1.rs b/rustlings/exercises/19_smart_pointers/arc1.rs
deleted file mode 100644
index f44e4e1..0000000
--- a/rustlings/exercises/19_smart_pointers/arc1.rs
+++ /dev/null
@@ -1,45 +0,0 @@
-// In this exercise, we are given a `Vec` of `u32` called `numbers` with values
-// ranging from 0 to 99. We would like to use this set of numbers within 8
-// different threads simultaneously. Each thread is going to get the sum of
-// every eighth value with an offset.
-//
-// The first thread (offset 0), will sum 0, 8, 16, …
-// The second thread (offset 1), will sum 1, 9, 17, …
-// The third thread (offset 2), will sum 2, 10, 18, …
-// …
-// The eighth thread (offset 7), will sum 7, 15, 23, …
-//
-// Each thread should own a reference-counting pointer to the vector of
-// numbers. But `Rc` isn't thread-safe. Therefore, we need to use `Arc`.
-//
-// Don't get distracted by how threads are spawned and joined. We will practice
-// that later in the exercises about threads.
-
-// Don't change the lines below.
-#![forbid(unused_imports)]
-use std::{sync::Arc, thread};
-
-fn main() {
-    let numbers: Vec<_> = (0..100u32).collect();
-
-    // TODO: Define `shared_numbers` by using `Arc`.
-    let shared_numbers = Arc::new(numbers);
-
-    let mut join_handles = Vec::new();
-
-    for offset in 0..8 {
-        // TODO: Define `child_numbers` using `shared_numbers`.
-        let child_numbers = shared_numbers.clone();
-
-        let handle = thread::spawn(move || {
-            let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum();
-            println!("Sum of offset {offset} is {sum}");
-        });
-
-        join_handles.push(handle);
-    }
-
-    for handle in join_handles.into_iter() {
-        handle.join().unwrap();
-    }
-}
diff --git a/rustlings/exercises/19_smart_pointers/box1.rs b/rustlings/exercises/19_smart_pointers/box1.rs
deleted file mode 100644
index ee379ca..0000000
--- a/rustlings/exercises/19_smart_pointers/box1.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-// At compile time, Rust needs to know how much space a type takes up. This
-// becomes problematic for recursive types, where a value can have as part of
-// itself another value of the same type. To get around the issue, we can use a
-// `Box` - a smart pointer used to store data on the heap, which also allows us
-// to wrap a recursive type.
-//
-// The recursive type we're implementing in this exercise is the "cons list", a
-// data structure frequently found in functional programming languages. Each
-// item in a cons list contains two elements: The value of the current item and
-// the next item. The last item is a value called `Nil`.
-
-// TODO: Use a `Box` in the enum definition to make the code compile.
-#[derive(PartialEq, Debug)]
-enum List {
-    Cons(i32, Box<List>),
-    Nil,
-}
-
-// TODO: Create an empty cons list.
-fn create_empty_list() -> List {
-    List::Nil
-}
-
-// TODO: Create a non-empty cons list.
-fn create_non_empty_list() -> List {
-    List::Cons(1, Box::new(List::Nil))
-}
-
-fn main() {
-    println!("This is an empty cons list: {:?}", create_empty_list());
-    println!(
-        "This is a non-empty cons list: {:?}",
-        create_non_empty_list(),
-    );
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_create_empty_list() {
-        assert_eq!(create_empty_list(), List::Nil);
-    }
-
-    #[test]
-    fn test_create_non_empty_list() {
-        assert_ne!(create_empty_list(), create_non_empty_list());
-    }
-}
diff --git a/rustlings/exercises/19_smart_pointers/cow1.rs b/rustlings/exercises/19_smart_pointers/cow1.rs
deleted file mode 100644
index 56a25b9..0000000
--- a/rustlings/exercises/19_smart_pointers/cow1.rs
+++ /dev/null
@@ -1,66 +0,0 @@
-// This exercise explores the `Cow` (Clone-On-Write) smart pointer. It can
-// enclose and provide immutable access to borrowed data and clone the data
-// lazily when mutation or ownership is required. The type is designed to work
-// with general borrowed data via the `Borrow` trait.
-
-use std::borrow::Cow;
-
-fn abs_all(input: &mut Cow<[i32]>) {
-    for ind in 0..input.len() {
-        let value = input[ind];
-        if value < 0 {
-            // Clones into a vector if not already owned.
-            input.to_mut()[ind] = -value;
-        }
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn reference_mutation() {
-        // Clone occurs because `input` needs to be mutated.
-        let vec = vec![-1, 0, 1];
-        let mut input = Cow::from(&vec);
-        abs_all(&mut input);
-        assert!(matches!(input, Cow::Owned(_)));
-    }
-
-    #[test]
-    fn reference_no_mutation() {
-        // No clone occurs because `input` doesn't need to be mutated.
-        let vec = vec![0, 1, 2];
-        let mut input = Cow::from(&vec);
-        abs_all(&mut input);
-        assert!(matches!(input, Cow::Borrowed(_)));
-    }
-
-    #[test]
-    fn owned_no_mutation() {
-        // We can also pass `vec` without `&` so `Cow` owns it directly. In this
-        // case, no mutation occurs (all numbers are already absolute) and thus
-        // also no clone. But the result is still owned because it was never
-        // borrowed or mutated.
-        let vec = vec![0, 1, 2];
-        let mut input = Cow::from(vec);
-        abs_all(&mut input);
-        assert!(matches!(input, Cow::Owned(_)));
-    }
-
-    #[test]
-    fn owned_mutation() {
-        // Of course this is also the case if a mutation does occur (not all
-        // numbers are absolute). In this case, the call to `to_mut()` in the
-        // `abs_all` function returns a reference to the same data as before.
-        let vec = vec![-1, 0, 1];
-        let mut input = Cow::from(vec);
-        abs_all(&mut input);
-        assert!(matches!(input, Cow::Owned(_)));
-    }
-}
diff --git a/rustlings/exercises/19_smart_pointers/rc1.rs b/rustlings/exercises/19_smart_pointers/rc1.rs
deleted file mode 100644
index 5c9ce84..0000000
--- a/rustlings/exercises/19_smart_pointers/rc1.rs
+++ /dev/null
@@ -1,108 +0,0 @@
-// In this exercise, we want to express the concept of multiple owners via the
-// `Rc<T>` type. This is a model of our solar system - there is a `Sun` type and
-// multiple `Planet`s. The planets take ownership of the sun, indicating that
-// they revolve around the sun.
-
-use std::rc::Rc;
-
-#[derive(Debug)]
-struct Sun;
-
-#[derive(Debug)]
-enum Planet {
-    Mercury(Rc<Sun>),
-    Venus(Rc<Sun>),
-    Earth(Rc<Sun>),
-    Mars(Rc<Sun>),
-    Jupiter(Rc<Sun>),
-    Saturn(Rc<Sun>),
-    Uranus(Rc<Sun>),
-    Neptune(Rc<Sun>),
-}
-
-impl Planet {
-    fn details(&self) {
-        println!("Hi from {self:?}!");
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn rc1() {
-        let sun = Rc::new(Sun);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
-
-        let mercury = Planet::Mercury(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
-        mercury.details();
-
-        let venus = Planet::Venus(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
-        venus.details();
-
-        let earth = Planet::Earth(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
-        earth.details();
-
-        let mars = Planet::Mars(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 5 references
-        mars.details();
-
-        let jupiter = Planet::Jupiter(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 6 references
-        jupiter.details();
-
-        // TODO
-        let saturn = Planet::Saturn(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
-        saturn.details();
-
-        // TODO
-        let uranus = Planet::Uranus(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
-        uranus.details();
-
-        // TODO
-        let neptune = Planet::Neptune(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
-        neptune.details();
-
-        assert_eq!(Rc::strong_count(&sun), 9);
-
-        drop(neptune);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
-
-        drop(uranus);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
-
-        drop(saturn);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 6 references
-
-        drop(jupiter);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 5 references
-
-        drop(mars);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
-
-        // TODO
-        drop(earth);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
-
-        // TODO
-        drop(venus);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
-
-        // TODO
-        drop(mercury);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
-
-        assert_eq!(Rc::strong_count(&sun), 1);
-    }
-}
diff --git a/rustlings/exercises/20_threads/README.md b/rustlings/exercises/20_threads/README.md
deleted file mode 100644
index 0b32fb1..0000000
--- a/rustlings/exercises/20_threads/README.md
+++ /dev/null
@@ -1,10 +0,0 @@
-# Threads
-
-In most current operating systems, an executed program's code is run in a process, and the operating system manages multiple processes at once.
-Within your program, you can also have independent parts that run simultaneously. The features that run these independent parts are called threads.
-
-## Further information
-
-- [Dining Philosophers example](https://doc.rust-lang.org/1.4.0/book/dining-philosophers.html)
-- [Using Threads to Run Code Simultaneously](https://doc.rust-lang.org/book/ch16-01-threads.html)
-- [Using Message Passing to Transfer Data Between Threads](https://doc.rust-lang.org/book/ch16-02-message-passing.html)
diff --git a/rustlings/exercises/20_threads/threads1.rs b/rustlings/exercises/20_threads/threads1.rs
deleted file mode 100644
index dbc64b1..0000000
--- a/rustlings/exercises/20_threads/threads1.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-// This program spawns multiple threads that each runs for at least 250ms, and
-// each thread returns how much time it took to complete. The program should
-// wait until all the spawned threads have finished and should collect their
-// return values into a vector.
-
-use std::{
-    thread,
-    time::{Duration, Instant},
-};
-
-fn main() {
-    let mut handles = Vec::new();
-    for i in 0..10 {
-        let handle = thread::spawn(move || {
-            let start = Instant::now();
-            thread::sleep(Duration::from_millis(250));
-            println!("Thread {i} done");
-            start.elapsed().as_millis()
-        });
-        handles.push(handle);
-    }
-
-    let mut results = Vec::new();
-    for handle in handles {
-        // TODO: Collect the results of all threads into the `results` vector.
-        // Use the `JoinHandle` struct which is returned by `thread::spawn`.
-    }
-
-    if results.len() != 10 {
-        panic!("Oh no! Some thread isn't done yet!");
-    }
-
-    println!();
-    for (i, result) in results.into_iter().enumerate() {
-        println!("Thread {i} took {result}ms");
-    }
-}
diff --git a/rustlings/exercises/20_threads/threads2.rs b/rustlings/exercises/20_threads/threads2.rs
deleted file mode 100644
index 7020cb9..0000000
--- a/rustlings/exercises/20_threads/threads2.rs
+++ /dev/null
@@ -1,34 +0,0 @@
-// Building on the last exercise, we want all of the threads to complete their
-// work. But this time, the spawned threads need to be in charge of updating a
-// shared value: `JobStatus.jobs_done`
-
-use std::{sync::Arc, thread, time::Duration};
-
-struct JobStatus {
-    jobs_done: u32,
-}
-
-fn main() {
-    // TODO: `Arc` isn't enough if you want a **mutable** shared state.
-    let status = Arc::new(JobStatus { jobs_done: 0 });
-
-    let mut handles = Vec::new();
-    for _ in 0..10 {
-        let status_shared = Arc::clone(&status);
-        let handle = thread::spawn(move || {
-            thread::sleep(Duration::from_millis(250));
-
-            // TODO: You must take an action before you update a shared value.
-            status_shared.jobs_done += 1;
-        });
-        handles.push(handle);
-    }
-
-    // Waiting for all jobs to complete.
-    for handle in handles {
-        handle.join().unwrap();
-    }
-
-    // TODO: Print the value of `JobStatus.jobs_done`.
-    println!("Jobs done: {}", todo!());
-}
diff --git a/rustlings/exercises/20_threads/threads3.rs b/rustlings/exercises/20_threads/threads3.rs
deleted file mode 100644
index 6d16bd9..0000000
--- a/rustlings/exercises/20_threads/threads3.rs
+++ /dev/null
@@ -1,60 +0,0 @@
-use std::{sync::mpsc, thread, time::Duration};
-
-struct Queue {
-    first_half: Vec<u32>,
-    second_half: Vec<u32>,
-}
-
-impl Queue {
-    fn new() -> Self {
-        Self {
-            first_half: vec![1, 2, 3, 4, 5],
-            second_half: vec![6, 7, 8, 9, 10],
-        }
-    }
-}
-
-fn send_tx(q: Queue, tx: mpsc::Sender<u32>) {
-    // TODO: We want to send `tx` to both threads. But currently, it is moved
-    // into the first thread. How could you solve this problem?
-    thread::spawn(move || {
-        for val in q.first_half {
-            println!("Sending {val:?}");
-            tx.send(val).unwrap();
-            thread::sleep(Duration::from_millis(250));
-        }
-    });
-
-    thread::spawn(move || {
-        for val in q.second_half {
-            println!("Sending {val:?}");
-            tx.send(val).unwrap();
-            thread::sleep(Duration::from_millis(250));
-        }
-    });
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn threads3() {
-        let (tx, rx) = mpsc::channel();
-        let queue = Queue::new();
-
-        send_tx(queue, tx);
-
-        let mut received = Vec::with_capacity(10);
-        for value in rx {
-            received.push(value);
-        }
-
-        received.sort();
-        assert_eq!(received, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
-    }
-}
diff --git a/rustlings/exercises/21_macros/README.md b/rustlings/exercises/21_macros/README.md
deleted file mode 100644
index de7fb7b..0000000
--- a/rustlings/exercises/21_macros/README.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# Macros
-
-Rust's macro system is very powerful, but also kind of difficult to wrap your
-head around. We're not going to teach you how to write your own fully-featured
-macros. Instead, we'll show you how to use and create them.
-
-If you'd like to learn more about writing your own macros, the
-[macrokata](https://github.com/tfpk/macrokata) project has a similar style
-of exercises to Rustlings, but is all about learning to write Macros.
-
-## Further information
-
-- [The Rust Book - Macros](https://doc.rust-lang.org/book/ch20-05-macros.html)
-- [The Little Book of Rust Macros](https://veykril.github.io/tlborm/)
-- [Rust by Example - macro_rules!](https://doc.rust-lang.org/rust-by-example/macros.html)
diff --git a/rustlings/exercises/21_macros/macros1.rs b/rustlings/exercises/21_macros/macros1.rs
deleted file mode 100644
index fb3c3ff..0000000
--- a/rustlings/exercises/21_macros/macros1.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-macro_rules! my_macro {
-    () => {
-        println!("Check out my macro!");
-    };
-}
-
-fn main() {
-    // TODO: Fix the macro call.
-    my_macro();
-}
diff --git a/rustlings/exercises/21_macros/macros2.rs b/rustlings/exercises/21_macros/macros2.rs
deleted file mode 100644
index 2d9dec7..0000000
--- a/rustlings/exercises/21_macros/macros2.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-fn main() {
-    my_macro!();
-}
-
-// TODO: Fix the compiler error by moving the whole definition of this macro.
-macro_rules! my_macro {
-    () => {
-        println!("Check out my macro!");
-    };
-}
diff --git a/rustlings/exercises/21_macros/macros3.rs b/rustlings/exercises/21_macros/macros3.rs
deleted file mode 100644
index 9537494..0000000
--- a/rustlings/exercises/21_macros/macros3.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// TODO: Fix the compiler error without taking the macro definition out of this
-// module.
-mod macros {
-    macro_rules! my_macro {
-        () => {
-            println!("Check out my macro!");
-        };
-    }
-}
-
-fn main() {
-    my_macro!();
-}
diff --git a/rustlings/exercises/21_macros/macros4.rs b/rustlings/exercises/21_macros/macros4.rs
deleted file mode 100644
index 9d77f6a..0000000
--- a/rustlings/exercises/21_macros/macros4.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-// TODO: Fix the compiler error by adding one or two characters.
-#[rustfmt::skip]
-macro_rules! my_macro {
-    () => {
-        println!("Check out my macro!");
-    }
-    ($val:expr) => {
-        println!("Look at this other macro: {}", $val);
-    }
-}
-
-fn main() {
-    my_macro!();
-    my_macro!(7777);
-}
diff --git a/rustlings/exercises/22_clippy/README.md b/rustlings/exercises/22_clippy/README.md
deleted file mode 100644
index 55438af..0000000
--- a/rustlings/exercises/22_clippy/README.md
+++ /dev/null
@@ -1,10 +0,0 @@
-# Clippy
-
-The Clippy tool is a collection of lints to analyze your code so you can catch common mistakes and improve your Rust code.
-
-If you used the installation script for Rustlings, Clippy should be already installed.
-If not you can install it manually via `rustup component add clippy`.
-
-## Further information
-
-- [GitHub Repository](https://github.com/rust-lang/rust-clippy).
diff --git a/rustlings/exercises/22_clippy/clippy1.rs b/rustlings/exercises/22_clippy/clippy1.rs
deleted file mode 100644
index 7165da4..0000000
--- a/rustlings/exercises/22_clippy/clippy1.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-// The Clippy tool is a collection of lints to analyze your code so you can
-// catch common mistakes and improve your Rust code.
-//
-// For these exercises, the code will fail to compile when there are Clippy
-// warnings. Check Clippy's suggestions from the output to solve the exercise.
-
-fn main() {
-    // TODO: Fix the Clippy lint in this line.
-    let pi = 3.14;
-    let radius: f32 = 5.0;
-
-    let area = pi * radius.powi(2);
-
-    println!("The area of a circle with radius {radius:.2} is {area:.5}");
-}
diff --git a/rustlings/exercises/22_clippy/clippy2.rs b/rustlings/exercises/22_clippy/clippy2.rs
deleted file mode 100644
index 8cfe6f8..0000000
--- a/rustlings/exercises/22_clippy/clippy2.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-fn main() {
-    let mut res = 42;
-    let option = Some(12);
-    // TODO: Fix the Clippy lint.
-    for x in option {
-        res += x;
-    }
-
-    println!("{res}");
-}
diff --git a/rustlings/exercises/22_clippy/clippy3.rs b/rustlings/exercises/22_clippy/clippy3.rs
deleted file mode 100644
index 7a3cb39..0000000
--- a/rustlings/exercises/22_clippy/clippy3.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-// Here are some more easy Clippy fixes so you can see its utility 📎
-// TODO: Fix all the Clippy lints.
-
-#[rustfmt::skip]
-#[allow(unused_variables, unused_assignments)]
-fn main() {
-    let my_option: Option<&str> = None;
-    // Assume that you don't know the value of `my_option`.
-    // In the case of `Some`, we want to print its value.
-    if my_option.is_none() {
-        println!("{}", my_option.unwrap());
-    }
-
-    let my_arr = &[
-        -1, -2, -3
-        -4, -5, -6
-    ];
-    println!("My array! Here it is: {my_arr:?}");
-
-    let my_empty_vec = vec![1, 2, 3, 4, 5].resize(0, 5);
-    println!("This Vec is empty, see? {my_empty_vec:?}");
-
-    let mut value_a = 45;
-    let mut value_b = 66;
-    // Let's swap these two!
-    value_a = value_b;
-    value_b = value_a;
-    println!("value a: {value_a}; value b: {value_b}");
-}
diff --git a/rustlings/exercises/23_conversions/README.md b/rustlings/exercises/23_conversions/README.md
deleted file mode 100644
index 619a78c..0000000
--- a/rustlings/exercises/23_conversions/README.md
+++ /dev/null
@@ -1,23 +0,0 @@
-# Type conversions
-
-Rust offers a multitude of ways to convert a value of a given type into another type.
-
-The simplest form of type conversion is a type cast expression. It is denoted with the binary operator `as`. For instance, `println!("{}", 1 + 1.0);` would not compile, since `1` is an integer while `1.0` is a float. However, `println!("{}", 1 as f32 + 1.0)` should compile. The exercise [`using_as`](using_as.rs) tries to cover this.
-
-Rust also offers traits that facilitate type conversions upon implementation. These traits can be found under the [`convert`](https://doc.rust-lang.org/std/convert/index.html) module.
-The traits are the following:
-
-- `From` and `Into` covered in [`from_into`](from_into.rs)
-- `TryFrom` and `TryInto` covered in [`try_from_into`](try_from_into.rs)
-- `AsRef` and `AsMut` covered in [`as_ref_mut`](as_ref_mut.rs)
-
-Furthermore, the `std::str` module offers a trait called [`FromStr`](https://doc.rust-lang.org/std/str/trait.FromStr.html) which helps with converting strings into target types via the `parse` method on strings. If properly implemented for a given type `Person`, then `let p: Person = "Mark,20".parse().unwrap()` should both compile and run without panicking.
-
-These should be the main ways ***within the standard library*** to convert data into your desired types.
-
-## Further information
-
-These are not directly covered in the book, but the standard library has a great documentation for it.
-
-- [conversions](https://doc.rust-lang.org/std/convert/index.html)
-- [`FromStr` trait](https://doc.rust-lang.org/std/str/trait.FromStr.html)
diff --git a/rustlings/exercises/23_conversions/as_ref_mut.rs b/rustlings/exercises/23_conversions/as_ref_mut.rs
deleted file mode 100644
index d7892dd..0000000
--- a/rustlings/exercises/23_conversions/as_ref_mut.rs
+++ /dev/null
@@ -1,62 +0,0 @@
-// AsRef and AsMut allow for cheap reference-to-reference conversions. Read more
-// about them at https://doc.rust-lang.org/std/convert/trait.AsRef.html and
-// https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
-
-// Obtain the number of bytes (not characters) in the given argument
-// (`.len()` returns the number of bytes in a string).
-// TODO: Add the `AsRef` trait appropriately as a trait bound.
-fn byte_counter<T>(arg: T) -> usize {
-    arg.as_ref().len()
-}
-
-// Obtain the number of characters (not bytes) in the given argument.
-// TODO: Add the `AsRef` trait appropriately as a trait bound.
-fn char_counter<T>(arg: T) -> usize {
-    arg.as_ref().chars().count()
-}
-
-// Squares a number using `as_mut()`.
-// TODO: Add the appropriate trait bound.
-fn num_sq<T>(arg: &mut T) {
-    // TODO: Implement the function body.
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn different_counts() {
-        let s = "Café au lait";
-        assert_ne!(char_counter(s), byte_counter(s));
-    }
-
-    #[test]
-    fn same_counts() {
-        let s = "Cafe au lait";
-        assert_eq!(char_counter(s), byte_counter(s));
-    }
-
-    #[test]
-    fn different_counts_using_string() {
-        let s = String::from("Café au lait");
-        assert_ne!(char_counter(s.clone()), byte_counter(s));
-    }
-
-    #[test]
-    fn same_counts_using_string() {
-        let s = String::from("Cafe au lait");
-        assert_eq!(char_counter(s.clone()), byte_counter(s));
-    }
-
-    #[test]
-    fn mut_box() {
-        let mut num: Box<u32> = Box::new(3);
-        num_sq(&mut num);
-        assert_eq!(*num, 9);
-    }
-}
diff --git a/rustlings/exercises/23_conversions/from_into.rs b/rustlings/exercises/23_conversions/from_into.rs
deleted file mode 100644
index bc2783a..0000000
--- a/rustlings/exercises/23_conversions/from_into.rs
+++ /dev/null
@@ -1,130 +0,0 @@
-// The `From` trait is used for value-to-value conversions. If `From` is
-// implemented, an implementation of `Into` is automatically provided.
-// You can read more about it in the documentation:
-// https://doc.rust-lang.org/std/convert/trait.From.html
-
-#[derive(Debug)]
-struct Person {
-    name: String,
-    age: u8,
-}
-
-// We implement the Default trait to use it as a fallback when the provided
-// string is not convertible into a `Person` object.
-impl Default for Person {
-    fn default() -> Self {
-        Self {
-            name: String::from("John"),
-            age: 30,
-        }
-    }
-}
-
-// TODO: Complete this `From` implementation to be able to parse a `Person`
-// out of a string in the form of "Mark,20".
-// Note that you'll need to parse the age component into a `u8` with something
-// like `"4".parse::<u8>()`.
-//
-// Steps:
-// 1. Split the given string on the commas present in it.
-// 2. If the split operation returns less or more than 2 elements, return the
-//    default of `Person`.
-// 3. Use the first element from the split operation as the name.
-// 4. If the name is empty, return the default of `Person`.
-// 5. Parse the second element from the split operation into a `u8` as the age.
-// 6. If parsing the age fails, return the default of `Person`.
-impl From<&str> for Person {
-    fn from(s: &str) -> Self {}
-}
-
-fn main() {
-    // Use the `from` function.
-    let p1 = Person::from("Mark,20");
-    println!("{p1:?}");
-
-    // Since `From` is implemented for Person, we are able to use `Into`.
-    let p2: Person = "Gerald,70".into();
-    println!("{p2:?}");
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_default() {
-        let dp = Person::default();
-        assert_eq!(dp.name, "John");
-        assert_eq!(dp.age, 30);
-    }
-
-    #[test]
-    fn test_bad_convert() {
-        let p = Person::from("");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_good_convert() {
-        let p = Person::from("Mark,20");
-        assert_eq!(p.name, "Mark");
-        assert_eq!(p.age, 20);
-    }
-
-    #[test]
-    fn test_bad_age() {
-        let p = Person::from("Mark,twenty");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_missing_comma_and_age() {
-        let p: Person = Person::from("Mark");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_missing_age() {
-        let p: Person = Person::from("Mark,");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_missing_name() {
-        let p: Person = Person::from(",1");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_missing_name_and_age() {
-        let p: Person = Person::from(",");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_missing_name_and_invalid_age() {
-        let p: Person = Person::from(",one");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_trailing_comma() {
-        let p: Person = Person::from("Mike,32,");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-
-    #[test]
-    fn test_trailing_comma_and_some_string() {
-        let p: Person = Person::from("Mike,32,dog");
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 30);
-    }
-}
diff --git a/rustlings/exercises/23_conversions/from_str.rs b/rustlings/exercises/23_conversions/from_str.rs
deleted file mode 100644
index ec6d3fd..0000000
--- a/rustlings/exercises/23_conversions/from_str.rs
+++ /dev/null
@@ -1,113 +0,0 @@
-// This is similar to the previous `from_into` exercise. But this time, we'll
-// implement `FromStr` and return errors instead of falling back to a default
-// value. Additionally, upon implementing `FromStr`, you can use the `parse`
-// method on strings to generate an object of the implementor type. You can read
-// more about it in the documentation:
-// https://doc.rust-lang.org/std/str/trait.FromStr.html
-
-use std::num::ParseIntError;
-use std::str::FromStr;
-
-#[derive(Debug, PartialEq)]
-struct Person {
-    name: String,
-    age: u8,
-}
-
-// We will use this error type for the `FromStr` implementation.
-#[derive(Debug, PartialEq)]
-enum ParsePersonError {
-    // Incorrect number of fields
-    BadLen,
-    // Empty name field
-    NoName,
-    // Wrapped error from parse::<u8>()
-    ParseInt(ParseIntError),
-}
-
-// TODO: Complete this `FromStr` implementation to be able to parse a `Person`
-// out of a string in the form of "Mark,20".
-// Note that you'll need to parse the age component into a `u8` with something
-// like `"4".parse::<u8>()`.
-//
-// Steps:
-// 1. Split the given string on the commas present in it.
-// 2. If the split operation returns less or more than 2 elements, return the
-//    error `ParsePersonError::BadLen`.
-// 3. Use the first element from the split operation as the name.
-// 4. If the name is empty, return the error `ParsePersonError::NoName`.
-// 5. Parse the second element from the split operation into a `u8` as the age.
-// 6. If parsing the age fails, return the error `ParsePersonError::ParseInt`.
-impl FromStr for Person {
-    type Err = ParsePersonError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {}
-}
-
-fn main() {
-    let p = "Mark,20".parse::<Person>();
-    println!("{p:?}");
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use ParsePersonError::*;
-
-    #[test]
-    fn empty_input() {
-        assert_eq!("".parse::<Person>(), Err(BadLen));
-    }
-
-    #[test]
-    fn good_input() {
-        let p = "John,32".parse::<Person>();
-        assert!(p.is_ok());
-        let p = p.unwrap();
-        assert_eq!(p.name, "John");
-        assert_eq!(p.age, 32);
-    }
-
-    #[test]
-    fn missing_age() {
-        assert!(matches!("John,".parse::<Person>(), Err(ParseInt(_))));
-    }
-
-    #[test]
-    fn invalid_age() {
-        assert!(matches!("John,twenty".parse::<Person>(), Err(ParseInt(_))));
-    }
-
-    #[test]
-    fn missing_comma_and_age() {
-        assert_eq!("John".parse::<Person>(), Err(BadLen));
-    }
-
-    #[test]
-    fn missing_name() {
-        assert_eq!(",1".parse::<Person>(), Err(NoName));
-    }
-
-    #[test]
-    fn missing_name_and_age() {
-        assert!(matches!(",".parse::<Person>(), Err(NoName | ParseInt(_))));
-    }
-
-    #[test]
-    fn missing_name_and_invalid_age() {
-        assert!(matches!(
-            ",one".parse::<Person>(),
-            Err(NoName | ParseInt(_)),
-        ));
-    }
-
-    #[test]
-    fn trailing_comma() {
-        assert_eq!("John,32,".parse::<Person>(), Err(BadLen));
-    }
-
-    #[test]
-    fn trailing_comma_and_some_string() {
-        assert_eq!("John,32,man".parse::<Person>(), Err(BadLen));
-    }
-}
diff --git a/rustlings/exercises/23_conversions/try_from_into.rs b/rustlings/exercises/23_conversions/try_from_into.rs
deleted file mode 100644
index f3ae80a..0000000
--- a/rustlings/exercises/23_conversions/try_from_into.rs
+++ /dev/null
@@ -1,177 +0,0 @@
-// `TryFrom` is a simple and safe type conversion that may fail in a controlled
-// way under some circumstances. Basically, this is the same as `From`. The main
-// difference is that this should return a `Result` type instead of the target
-// type itself. You can read more about it in the documentation:
-// https://doc.rust-lang.org/std/convert/trait.TryFrom.html
-
-#![allow(clippy::useless_vec)]
-use std::convert::{TryFrom, TryInto};
-
-#[derive(Debug, PartialEq)]
-struct Color {
-    red: u8,
-    green: u8,
-    blue: u8,
-}
-
-// We will use this error type for the `TryFrom` conversions.
-#[derive(Debug, PartialEq)]
-enum IntoColorError {
-    // Incorrect length of slice
-    BadLen,
-    // Integer conversion error
-    IntConversion,
-}
-
-// TODO: Tuple implementation.
-// Correct RGB color values must be integers in the 0..=255 range.
-impl TryFrom<(i16, i16, i16)> for Color {
-    type Error = IntoColorError;
-
-    fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {}
-}
-
-// TODO: Array implementation.
-impl TryFrom<[i16; 3]> for Color {
-    type Error = IntoColorError;
-
-    fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {}
-}
-
-// TODO: Slice implementation.
-// This implementation needs to check the slice length.
-impl TryFrom<&[i16]> for Color {
-    type Error = IntoColorError;
-
-    fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {}
-}
-
-fn main() {
-    // Using the `try_from` function.
-    let c1 = Color::try_from((183, 65, 14));
-    println!("{c1:?}");
-
-    // Since `TryFrom` is implemented for `Color`, we can use `TryInto`.
-    let c2: Result<Color, _> = [183, 65, 14].try_into();
-    println!("{c2:?}");
-
-    let v = vec![183, 65, 14];
-    // With slice we should use the `try_from` function
-    let c3 = Color::try_from(&v[..]);
-    println!("{c3:?}");
-    // or put the slice within round brackets and use `try_into`.
-    let c4: Result<Color, _> = (&v[..]).try_into();
-    println!("{c4:?}");
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use IntoColorError::*;
-
-    #[test]
-    fn test_tuple_out_of_range_positive() {
-        assert_eq!(Color::try_from((256, 1000, 10000)), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_tuple_out_of_range_negative() {
-        assert_eq!(Color::try_from((-1, -10, -256)), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_tuple_sum() {
-        assert_eq!(Color::try_from((-1, 255, 255)), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_tuple_correct() {
-        let c: Result<Color, _> = (183, 65, 14).try_into();
-        assert!(c.is_ok());
-        assert_eq!(
-            c.unwrap(),
-            Color {
-                red: 183,
-                green: 65,
-                blue: 14,
-            }
-        );
-    }
-
-    #[test]
-    fn test_array_out_of_range_positive() {
-        let c: Result<Color, _> = [1000, 10000, 256].try_into();
-        assert_eq!(c, Err(IntConversion));
-    }
-
-    #[test]
-    fn test_array_out_of_range_negative() {
-        let c: Result<Color, _> = [-10, -256, -1].try_into();
-        assert_eq!(c, Err(IntConversion));
-    }
-
-    #[test]
-    fn test_array_sum() {
-        let c: Result<Color, _> = [-1, 255, 255].try_into();
-        assert_eq!(c, Err(IntConversion));
-    }
-
-    #[test]
-    fn test_array_correct() {
-        let c: Result<Color, _> = [183, 65, 14].try_into();
-        assert!(c.is_ok());
-        assert_eq!(
-            c.unwrap(),
-            Color {
-                red: 183,
-                green: 65,
-                blue: 14
-            }
-        );
-    }
-
-    #[test]
-    fn test_slice_out_of_range_positive() {
-        let arr = [10000, 256, 1000];
-        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_slice_out_of_range_negative() {
-        let arr = [-256, -1, -10];
-        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_slice_sum() {
-        let arr = [-1, 255, 255];
-        assert_eq!(Color::try_from(&arr[..]), Err(IntConversion));
-    }
-
-    #[test]
-    fn test_slice_correct() {
-        let v = vec![183, 65, 14];
-        let c: Result<Color, _> = Color::try_from(&v[..]);
-        assert!(c.is_ok());
-        assert_eq!(
-            c.unwrap(),
-            Color {
-                red: 183,
-                green: 65,
-                blue: 14,
-            }
-        );
-    }
-
-    #[test]
-    fn test_slice_excess_length() {
-        let v = vec![0, 0, 0, 0];
-        assert_eq!(Color::try_from(&v[..]), Err(BadLen));
-    }
-
-    #[test]
-    fn test_slice_insufficient_length() {
-        let v = vec![0, 0];
-        assert_eq!(Color::try_from(&v[..]), Err(BadLen));
-    }
-}
diff --git a/rustlings/exercises/23_conversions/using_as.rs b/rustlings/exercises/23_conversions/using_as.rs
deleted file mode 100644
index c131d1f..0000000
--- a/rustlings/exercises/23_conversions/using_as.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-// Type casting in Rust is done via the usage of the `as` operator.
-// Note that the `as` operator is not only used when type casting. It also helps
-// with renaming imports.
-
-fn average(values: &[f64]) -> f64 {
-    let total = values.iter().sum::<f64>();
-    // TODO: Make a conversion before dividing.
-    total / values.len()
-}
-
-fn main() {
-    let values = [3.5, 0.3, 13.0, 11.7];
-    println!("{}", average(&values));
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn returns_proper_type_and_value() {
-        assert_eq!(average(&[3.5, 0.3, 13.0, 11.7]), 7.125);
-    }
-}
diff --git a/rustlings/exercises/README.md b/rustlings/exercises/README.md
deleted file mode 100644
index 1df5cc3..0000000
--- a/rustlings/exercises/README.md
+++ /dev/null
@@ -1,27 +0,0 @@
-# Exercise to Book Chapter mapping
-
-| Exercise               | Book Chapter        |
-| ---------------------- | ------------------- |
-| variables              | §3.1                |
-| functions              | §3.3                |
-| if                     | §3.5                |
-| primitive_types        | §3.2, §4.3          |
-| vecs                   | §8.1                |
-| move_semantics         | §4.1-2              |
-| structs                | §5.1, §5.3          |
-| enums                  | §6, §18.3           |
-| strings                | §8.2                |
-| modules                | §7                  |
-| hashmaps               | §8.3                |
-| options                | §10.1               |
-| error_handling         | §9                  |
-| generics               | §10                 |
-| traits                 | §10.2               |
-| lifetimes              | §10.3               |
-| tests                  | §11.1               |
-| iterators              | §13.2-4             |
-| smart_pointers         | §15, §16.3          |
-| threads                | §16.1-3             |
-| macros                 | §20.5               |
-| clippy                 | Appendix D          |
-| conversions            | n/a                 |
diff --git a/rustlings/exercises/quizzes/README.md b/rustlings/exercises/quizzes/README.md
deleted file mode 100644
index 4d3bcd9..0000000
--- a/rustlings/exercises/quizzes/README.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# Quizzes
-
-After every couple of sections, there will be a quiz in this directory that'll test your knowledge on a bunch of sections at once.
diff --git a/rustlings/exercises/quizzes/quiz1.rs b/rustlings/exercises/quizzes/quiz1.rs
deleted file mode 100644
index b787d7e..0000000
--- a/rustlings/exercises/quizzes/quiz1.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-// This is a quiz for the following sections:
-// - Variables
-// - Functions
-// - If
-//
-// Mary is buying apples. The price of an apple is calculated as follows:
-// - An apple costs 2 rustbucks.
-// - However, if Mary buys more than 40 apples, the price of each apple in the
-// entire order is reduced to only 1 rustbuck!
-
-fn calculate_price_of_apples(n: i32) -> i32 {
-    if n > 40 {
-        n
-    } else {
-        2 * n
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-// Don't change the tests!
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn verify_test() {
-        assert_eq!(calculate_price_of_apples(35), 70);
-        assert_eq!(calculate_price_of_apples(40), 80);
-        assert_eq!(calculate_price_of_apples(41), 41);
-        assert_eq!(calculate_price_of_apples(65), 65);
-    }
-}
diff --git a/rustlings/exercises/quizzes/quiz2.rs b/rustlings/exercises/quizzes/quiz2.rs
deleted file mode 100644
index fd32810..0000000
--- a/rustlings/exercises/quizzes/quiz2.rs
+++ /dev/null
@@ -1,81 +0,0 @@
-// This is a quiz for the following sections:
-// - Strings
-// - Vecs
-// - Move semantics
-// - Modules
-// - Enums
-//
-// Let's build a little machine in the form of a function. As input, we're going
-// to give a list of strings and commands. These commands determine what action
-// is going to be applied to the string. It can either be:
-// - Uppercase the string
-// - Trim the string
-// - Append "bar" to the string a specified amount of times
-//
-// The exact form of this will be:
-// - The input is going to be a Vector of 2-length tuples,
-//   the first element is the string, the second one is the command.
-// - The output element is going to be a vector of strings.
-
-enum Command {
-    Uppercase,
-    Trim,
-    Append(usize),
-}
-
-mod my_module {
-    use super::Command;
-
-    // TODO: Complete the function as described above.
-    // pub fn transformer(input: ???) -> ??? { ??? }
-    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
-        let mut out = Vec::new();
-        for inp in input {
-            out.push(match inp.1 {
-                Command::Uppercase => inp.0.to_uppercase(),
-                Command::Trim      => String::from(inp.0.trim()),
-                Command::Append(n) => {
-                    let mut r = inp.0;
-                    for _ in 0..n {
-                        r += "bar";
-                    }
-                    r
-                }
-            });
-        }
-        out
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    // TODO: What do we need to import to have `transformer` in scope?
-    // use ???;
-    use super::Command;
-    use super::my_module::transformer;
-
-    #[test]
-    fn it_works() {
-        let input = vec![
-            ("hello".to_string(), Command::Uppercase),
-            (" all roads lead to rome! ".to_string(), Command::Trim),
-            ("foo".to_string(), Command::Append(1)),
-            ("bar".to_string(), Command::Append(5)),
-        ];
-        let output = transformer(input);
-
-        assert_eq!(
-            output,
-            [
-                "HELLO",
-                "all roads lead to rome!",
-                "foobar",
-                "barbarbarbarbarbar",
-            ]
-        );
-    }
-}
diff --git a/rustlings/exercises/quizzes/quiz3.rs b/rustlings/exercises/quizzes/quiz3.rs
deleted file mode 100644
index 5bb859f..0000000
--- a/rustlings/exercises/quizzes/quiz3.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-// This quiz tests:
-// - Generics
-// - Traits
-//
-// An imaginary magical school has a new report card generation system written
-// in Rust! Currently, the system only supports creating report cards where the
-// student's grade is represented numerically (e.g. 1.0 -> 5.5). However, the
-// school also issues alphabetical grades (A+ -> F-) and needs to be able to
-// print both types of report card!
-//
-// Make the necessary code changes in the struct `ReportCard` and the impl
-// block to support alphabetical report cards in addition to numerical ones.
-
-// TODO: Adjust the struct as described above.
-struct ReportCard<T> {
-    grade: T,
-    student_name: String,
-    student_age: u8,
-}
-
-// TODO: Adjust the impl block as described above.
-impl<T: std::fmt::Display> ReportCard<T> {
-    fn print(&self) -> String {
-        format!(
-            "{} ({}) - achieved a grade of {}",
-            &self.student_name, &self.student_age, &self.grade,
-        )
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn generate_numeric_report_card() {
-        let report_card = ReportCard {
-            grade: 2.1,
-            student_name: "Tom Wriggle".to_string(),
-            student_age: 12,
-        };
-        assert_eq!(
-            report_card.print(),
-            "Tom Wriggle (12) - achieved a grade of 2.1",
-        );
-    }
-
-    #[test]
-    fn generate_alphabetic_report_card() {
-        let report_card = ReportCard {
-            grade: "A+",
-            student_name: "Gary Plotter".to_string(),
-            student_age: 11,
-        };
-        assert_eq!(
-            report_card.print(),
-            "Gary Plotter (11) - achieved a grade of A+",
-        );
-    }
-}