rustlings: move to rust/

95 files changed, 0 insertions, 2966 deletions

diff --git a/rustlings/solutions/00_intro/intro1.rs b/rustlings/solutions/00_intro/intro1.rs
deleted file mode 100644
index 4fe8454..0000000
--- a/rustlings/solutions/00_intro/intro1.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-fn main() {
-    // Congratulations, you finished the first exercise 🎉
-    // As an introduction to Rustlings, the first exercise only required
-    // entering `n` in the terminal to go to the next exercise.
-}
diff --git a/rustlings/solutions/00_intro/intro2.rs b/rustlings/solutions/00_intro/intro2.rs
deleted file mode 100644
index b8e031a..0000000
--- a/rustlings/solutions/00_intro/intro2.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // `println!` instead of `printline!`.
-    println!("Hello world!");
-}
diff --git a/rustlings/solutions/01_variables/variables1.rs b/rustlings/solutions/01_variables/variables1.rs
deleted file mode 100644
index 58d046b..0000000
--- a/rustlings/solutions/01_variables/variables1.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-fn main() {
-    // Declaring variables requires the `let` keyword.
-    let x = 5;
-
-    println!("x has the value {x}");
-}
diff --git a/rustlings/solutions/01_variables/variables2.rs b/rustlings/solutions/01_variables/variables2.rs
deleted file mode 100644
index 50b8d1b..0000000
--- a/rustlings/solutions/01_variables/variables2.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-fn main() {
-    // The easiest way to fix the compiler error is to initialize the
-    // variable `x`. By setting its value to an integer, Rust infers its type
-    // as `i32` which is the default type for integers.
-    let x = 42;
-
-    // But we can enforce a type different from the default `i32` by adding
-    // a type annotation:
-    // let x: u8 = 42;
-
-    if x == 10 {
-        println!("x is ten!");
-    } else {
-        println!("x is not ten!");
-    }
-}
diff --git a/rustlings/solutions/01_variables/variables3.rs b/rustlings/solutions/01_variables/variables3.rs
deleted file mode 100644
index 15f6557..0000000
--- a/rustlings/solutions/01_variables/variables3.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-#![allow(clippy::needless_late_init)]
-
-fn main() {
-    // Reading uninitialized variables isn't allowed in Rust!
-    // Therefore, we need to assign a value first.
-    let x: i32 = 42;
-
-    println!("Number {x}");
-
-    // It is possible to declare a variable and initialize it later.
-    // But it can't be used before initialization.
-    let y: i32;
-    y = 42;
-    println!("Number {y}");
-}
diff --git a/rustlings/solutions/01_variables/variables4.rs b/rustlings/solutions/01_variables/variables4.rs
deleted file mode 100644
index 7de6bcb..0000000
--- a/rustlings/solutions/01_variables/variables4.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn main() {
-    // In Rust, variables are immutable by default.
-    // Adding the `mut` keyword after `let` makes the declared variable mutable.
-    let mut x = 3;
-    println!("Number {x}");
-
-    x = 5;
-    println!("Number {x}");
-}
diff --git a/rustlings/solutions/01_variables/variables5.rs b/rustlings/solutions/01_variables/variables5.rs
deleted file mode 100644
index 0ea3903..0000000
--- a/rustlings/solutions/01_variables/variables5.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn main() {
-    let number = "T-H-R-E-E";
-    println!("Spell a number: {number}");
-
-    // Using variable shadowing
-    // https://doc.rust-lang.org/book/ch03-01-variables-and-mutability.html#shadowing
-    let number = 3;
-    println!("Number plus two is: {}", number + 2);
-}
diff --git a/rustlings/solutions/01_variables/variables6.rs b/rustlings/solutions/01_variables/variables6.rs
deleted file mode 100644
index 25b7a1e..0000000
--- a/rustlings/solutions/01_variables/variables6.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-// The type of constants must always be annotated.
-const NUMBER: u64 = 3;
-
-fn main() {
-    println!("Number: {NUMBER}");
-}
diff --git a/rustlings/solutions/02_functions/functions1.rs b/rustlings/solutions/02_functions/functions1.rs
deleted file mode 100644
index dc52744..0000000
--- a/rustlings/solutions/02_functions/functions1.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-// Some function with the name `call_me` without arguments or a return value.
-fn call_me() {
-    println!("Hello world!");
-}
-
-fn main() {
-    call_me();
-}
diff --git a/rustlings/solutions/02_functions/functions2.rs b/rustlings/solutions/02_functions/functions2.rs
deleted file mode 100644
index f14ffa3..0000000
--- a/rustlings/solutions/02_functions/functions2.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-// The type of function arguments must be annotated.
-// Added the type annotation `u64`.
-fn call_me(num: u64) {
-    for i in 0..num {
-        println!("Ring! Call number {}", i + 1);
-    }
-}
-
-fn main() {
-    call_me(3);
-}
diff --git a/rustlings/solutions/02_functions/functions3.rs b/rustlings/solutions/02_functions/functions3.rs
deleted file mode 100644
index ce5fe8e..0000000
--- a/rustlings/solutions/02_functions/functions3.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-fn call_me(num: u8) {
-    for i in 0..num {
-        println!("Ring! Call number {}", i + 1);
-    }
-}
-
-fn main() {
-    // `call_me` expects an argument.
-    call_me(5);
-}
diff --git a/rustlings/solutions/02_functions/functions4.rs b/rustlings/solutions/02_functions/functions4.rs
deleted file mode 100644
index f823de2..0000000
--- a/rustlings/solutions/02_functions/functions4.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-fn is_even(num: i64) -> bool {
-    num % 2 == 0
-}
-
-// The return type must always be annotated.
-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/solutions/02_functions/functions5.rs b/rustlings/solutions/02_functions/functions5.rs
deleted file mode 100644
index 677f327..0000000
--- a/rustlings/solutions/02_functions/functions5.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn square(num: i32) -> i32 {
-    // Removed the semicolon `;` at the end of the line below to implicitly return the result.
-    num * num
-}
-
-fn main() {
-    let answer = square(3);
-    println!("The square of 3 is {answer}");
-}
diff --git a/rustlings/solutions/03_if/if1.rs b/rustlings/solutions/03_if/if1.rs
deleted file mode 100644
index 8512a60..0000000
--- a/rustlings/solutions/03_if/if1.rs
+++ /dev/null
@@ -1,28 +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/solutions/03_if/if2.rs b/rustlings/solutions/03_if/if2.rs
deleted file mode 100644
index 21c0dcd..0000000
--- a/rustlings/solutions/03_if/if2.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-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.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn yummy_food() {
-        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/solutions/03_if/if3.rs b/rustlings/solutions/03_if/if3.rs
deleted file mode 100644
index 571644d..0000000
--- a/rustlings/solutions/03_if/if3.rs
+++ /dev/null
@@ -1,53 +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 {
-        // Any unused identifier.
-        4
-    };
-
-    // Instead of such an identifier, you would use an enum in Rust.
-    // But we didn't get into enums yet.
-    if identifier == 1 {
-        "Beach"
-    } else if identifier == 2 {
-        "Burrow"
-    } else if identifier == 3 {
-        "Desert"
-    } else {
-        "Unknown"
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[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/solutions/04_primitive_types/primitive_types1.rs b/rustlings/solutions/04_primitive_types/primitive_types1.rs
deleted file mode 100644
index fac6ec0..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types1.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-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/solutions/04_primitive_types/primitive_types2.rs b/rustlings/solutions/04_primitive_types/primitive_types2.rs
deleted file mode 100644
index eecc680..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types2.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-fn main() {
-    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!");
-    }
-
-    // Example with an emoji.
-    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/solutions/04_primitive_types/primitive_types3.rs b/rustlings/solutions/04_primitive_types/primitive_types3.rs
deleted file mode 100644
index 8dd109f..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types3.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-fn main() {
-    // An array with 100 elements of the value 42.
-    let a = [42; 100];
-
-    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/solutions/04_primitive_types/primitive_types4.rs b/rustlings/solutions/04_primitive_types/primitive_types4.rs
deleted file mode 100644
index 4807e66..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types4.rs
+++ /dev/null
@@ -1,23 +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];
-        //       0  1  2  3  4  <- indices
-        //          -------
-        //             |
-        //             +--- slice
-
-        // Note that the upper index 4 is excluded.
-        let nice_slice = &a[1..4];
-        assert_eq!([2, 3, 4], nice_slice);
-
-        // The upper index can be included by using the syntax `..=` (with `=` sign)
-        let nice_slice = &a[1..=3];
-        assert_eq!([2, 3, 4], nice_slice);
-    }
-}
diff --git a/rustlings/solutions/04_primitive_types/primitive_types5.rs b/rustlings/solutions/04_primitive_types/primitive_types5.rs
deleted file mode 100644
index 46d7ae8..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types5.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-fn main() {
-    let cat = ("Furry McFurson", 3.5);
-
-    // Destructuring the tuple.
-    let (name, age) = cat;
-
-    println!("{name} is {age} years old");
-}
diff --git a/rustlings/solutions/04_primitive_types/primitive_types6.rs b/rustlings/solutions/04_primitive_types/primitive_types6.rs
deleted file mode 100644
index 9b7c277..0000000
--- a/rustlings/solutions/04_primitive_types/primitive_types6.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn indexing_tuple() {
-        let numbers = (1, 2, 3);
-
-        // Tuple indexing syntax.
-        let second = numbers.1;
-
-        assert_eq!(second, 2, "This is not the 2nd number in the tuple!");
-    }
-}
diff --git a/rustlings/solutions/05_vecs/vecs1.rs b/rustlings/solutions/05_vecs/vecs1.rs
deleted file mode 100644
index 55b5676..0000000
--- a/rustlings/solutions/05_vecs/vecs1.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-fn array_and_vec() -> ([i32; 4], Vec<i32>) {
-    let a = [10, 20, 30, 40]; // Array
-
-    // Used the `vec!` macro.
-    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/solutions/05_vecs/vecs2.rs b/rustlings/solutions/05_vecs/vecs2.rs
deleted file mode 100644
index 87f7625..0000000
--- a/rustlings/solutions/05_vecs/vecs2.rs
+++ /dev/null
@@ -1,55 +0,0 @@
-fn vec_loop(input: &[i32]) -> Vec<i32> {
-    let mut output = Vec::new();
-
-    for element in input {
-        output.push(2 * element);
-    }
-
-    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> {
-    // We will dive deeper into iterators, but for now, this is all what you
-    // had to do!
-    // Advanced note: This method is more efficient because it automatically
-    // preallocates enough capacity. This can be done manually in `vec_loop`
-    // using `Vec::with_capacity(input.len())` instead of `Vec::new()`.
-    input.iter().map(|element| 2 * element).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/solutions/06_move_semantics/move_semantics1.rs b/rustlings/solutions/06_move_semantics/move_semantics1.rs
deleted file mode 100644
index ac34e7a..0000000
--- a/rustlings/solutions/06_move_semantics/move_semantics1.rs
+++ /dev/null
@@ -1,25 +0,0 @@
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
-    //  ^^^ added
-
-    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);
-        // `vec0` can't be accessed anymore because it is moved to `fill_vec`.
-        assert_eq!(vec1, vec![22, 44, 66, 88]);
-    }
-}
diff --git a/rustlings/solutions/06_move_semantics/move_semantics2.rs b/rustlings/solutions/06_move_semantics/move_semantics2.rs
deleted file mode 100644
index 7bcd33a..0000000
--- a/rustlings/solutions/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::*;
-
-    #[test]
-    fn move_semantics2() {
-        let vec0 = vec![22, 44, 66];
-
-        // Cloning `vec0` so that the clone is moved into `fill_vec`, not `vec0`
-        // itself.
-        let vec1 = fill_vec(vec0.clone());
-
-        assert_eq!(vec0, [22, 44, 66]);
-        assert_eq!(vec1, [22, 44, 66, 88]);
-    }
-}
diff --git a/rustlings/solutions/06_move_semantics/move_semantics3.rs b/rustlings/solutions/06_move_semantics/move_semantics3.rs
deleted file mode 100644
index 7ba4006..0000000
--- a/rustlings/solutions/06_move_semantics/move_semantics3.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
-    //      ^^^ added
-    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/solutions/06_move_semantics/move_semantics4.rs b/rustlings/solutions/06_move_semantics/move_semantics4.rs
deleted file mode 100644
index 1a39d4f..0000000
--- a/rustlings/solutions/06_move_semantics/move_semantics4.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn move_semantics4() {
-        let mut x = Vec::new();
-        let y = &mut x;
-        // `y` used here.
-        y.push(42);
-        // The mutable reference `y` is not used anymore,
-        // therefore a new reference can be created.
-        let z = &mut x;
-        z.push(13);
-        assert_eq!(x, [42, 13]);
-    }
-}
diff --git a/rustlings/solutions/06_move_semantics/move_semantics5.rs b/rustlings/solutions/06_move_semantics/move_semantics5.rs
deleted file mode 100644
index 1410e91..0000000
--- a/rustlings/solutions/06_move_semantics/move_semantics5.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-#![allow(clippy::ptr_arg)]
-
-// Borrows instead of taking ownership.
-// It is recommended to use `&str` instead of `&String` here. But this is
-// enough for now because we didn't handle strings yet.
-fn get_char(data: &String) -> char {
-    data.chars().last().unwrap()
-}
-
-// Takes ownership instead of borrowing.
-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/solutions/07_structs/structs1.rs b/rustlings/solutions/07_structs/structs1.rs
deleted file mode 100644
index 98fafcc..0000000
--- a/rustlings/solutions/07_structs/structs1.rs
+++ /dev/null
@@ -1,49 +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/solutions/07_structs/structs2.rs b/rustlings/solutions/07_structs/structs2.rs
deleted file mode 100644
index 589dd93..0000000
--- a/rustlings/solutions/07_structs/structs2.rs
+++ /dev/null
@@ -1,51 +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,
-            // Struct update syntax
-            ..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/solutions/07_structs/structs3.rs b/rustlings/solutions/07_structs/structs3.rs
deleted file mode 100644
index 3f878cc..0000000
--- a/rustlings/solutions/07_structs/structs3.rs
+++ /dev/null
@@ -1,83 +0,0 @@
-#[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 {
-        //                     ^^^^^^^ added
-        self.sender_country != self.recipient_country
-    }
-
-    fn get_fees(&self, cents_per_gram: u32) -> u32 {
-        //                                  ^^^^^^ added
-        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/solutions/08_enums/enums1.rs b/rustlings/solutions/08_enums/enums1.rs
deleted file mode 100644
index 97a5cc0..0000000
--- a/rustlings/solutions/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/solutions/08_enums/enums2.rs b/rustlings/solutions/08_enums/enums2.rs
deleted file mode 100644
index 07aee26..0000000
--- a/rustlings/solutions/08_enums/enums2.rs
+++ /dev/null
@@ -1,37 +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/solutions/08_enums/enums3.rs b/rustlings/solutions/08_enums/enums3.rs
deleted file mode 100644
index 94cf250..0000000
--- a/rustlings/solutions/08_enums/enums3.rs
+++ /dev/null
@@ -1,92 +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,
-    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(string) => self.echo(string),
-            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/solutions/09_strings/strings1.rs b/rustlings/solutions/09_strings/strings1.rs
deleted file mode 100644
index f7ba811..0000000
--- a/rustlings/solutions/09_strings/strings1.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn current_favorite_color() -> String {
-    // Equivalent to `String::from("blue")`
-    "blue".to_string()
-}
-
-fn main() {
-    let answer = current_favorite_color();
-    println!("My current favorite color is {answer}");
-}
diff --git a/rustlings/solutions/09_strings/strings2.rs b/rustlings/solutions/09_strings/strings2.rs
deleted file mode 100644
index 7de311f..0000000
--- a/rustlings/solutions/09_strings/strings2.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-fn is_a_color_word(attempt: &str) -> bool {
-    attempt == "green" || attempt == "blue" || attempt == "red"
-}
-
-fn main() {
-    let word = String::from("green");
-
-    if is_a_color_word(&word) {
-        //             ^ added to have `&String` which is automatically
-        //               coerced to `&str` by the compiler.
-        println!("That is a color word I know!");
-    } else {
-        println!("That is not a color word I know.");
-    }
-}
diff --git a/rustlings/solutions/09_strings/strings3.rs b/rustlings/solutions/09_strings/strings3.rs
deleted file mode 100644
index ee6b56a..0000000
--- a/rustlings/solutions/09_strings/strings3.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-fn trim_me(input: &str) -> &str {
-    input.trim()
-}
-
-fn compose_me(input: &str) -> String {
-    // The macro `format!` has the same syntax as `println!`, but it returns a
-    // string instead of printing it to the terminal.
-    // Equivalent to `input.to_string() + " world!"`
-    format!("{input} world!")
-}
-
-fn replace_me(input: &str) -> String {
-    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/solutions/09_strings/strings4.rs b/rustlings/solutions/09_strings/strings4.rs
deleted file mode 100644
index 3c69b97..0000000
--- a/rustlings/solutions/09_strings/strings4.rs
+++ /dev/null
@@ -1,38 +0,0 @@
-fn string_slice(arg: &str) {
-    println!("{arg}");
-}
-
-fn string(arg: String) {
-    println!("{arg}");
-}
-
-fn main() {
-    string_slice("blue");
-
-    string("red".to_string());
-
-    string(String::from("hi"));
-
-    string("rust is fun!".to_owned());
-
-    // Here, both answers work.
-    // `.into()` converts a type into an expected type.
-    // If it is called where `String` is expected, it will convert `&str` to `String`.
-    string("nice weather".into());
-    // But if it is called where `&str` is expected, then `&str` is kept `&str` since no conversion is needed.
-    // If you remove the `#[allow(…)]` line, then Clippy will tell you to remove `.into()` below since it is a useless conversion.
-    #[allow(clippy::useless_conversion)]
-    string_slice("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/solutions/10_modules/modules1.rs b/rustlings/solutions/10_modules/modules1.rs
deleted file mode 100644
index 873b412..0000000
--- a/rustlings/solutions/10_modules/modules1.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-mod sausage_factory {
-    fn get_secret_recipe() -> String {
-        String::from("Ginger")
-    }
-
-    // Added `pub` before `fn` to make the function accessible outside the module.
-    pub fn make_sausage() {
-        get_secret_recipe();
-        println!("sausage!");
-    }
-}
-
-fn main() {
-    sausage_factory::make_sausage();
-}
diff --git a/rustlings/solutions/10_modules/modules2.rs b/rustlings/solutions/10_modules/modules2.rs
deleted file mode 100644
index 55c316d..0000000
--- a/rustlings/solutions/10_modules/modules2.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-mod delicious_snacks {
-    // Added `pub` and used the expected alias after `as`.
-    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/solutions/10_modules/modules3.rs b/rustlings/solutions/10_modules/modules3.rs
deleted file mode 100644
index 99ff5a7..0000000
--- a/rustlings/solutions/10_modules/modules3.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-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/solutions/11_hashmaps/hashmaps1.rs b/rustlings/solutions/11_hashmaps/hashmaps1.rs
deleted file mode 100644
index 3a787c4..0000000
--- a/rustlings/solutions/11_hashmaps/hashmaps1.rs
+++ /dev/null
@@ -1,42 +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> {
-    // Declare the hash map.
-    let mut basket = HashMap::new();
-
-    // Two bananas are already given for you :)
-    basket.insert(String::from("banana"), 2);
-
-    // Put more fruits in your basket.
-    basket.insert(String::from("apple"), 3);
-    basket.insert(String::from("mango"), 1);
-
-    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/solutions/11_hashmaps/hashmaps2.rs b/rustlings/solutions/11_hashmaps/hashmaps2.rs
deleted file mode 100644
index 75e6ec2..0000000
--- a/rustlings/solutions/11_hashmaps/hashmaps2.rs
+++ /dev/null
@@ -1,96 +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 {
-        // If fruit doesn't exist, insert it with some value.
-        basket.entry(fruit).or_insert(5);
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    // Don't modify this function!
-    fn get_fruit_basket() -> HashMap<Fruit, u32> {
-        let content = [(Fruit::Apple, 4), (Fruit::Mango, 2), (Fruit::Lychee, 5)];
-        HashMap::from_iter(content)
-    }
-
-    #[test]
-    fn test_given_fruits_are_not_modified() {
-        let mut basket = get_fruit_basket();
-        fruit_basket(&mut basket);
-        assert_eq!(*basket.get(&Fruit::Apple).unwrap(), 4);
-        assert_eq!(*basket.get(&Fruit::Mango).unwrap(), 2);
-        assert_eq!(*basket.get(&Fruit::Lychee).unwrap(), 5);
-    }
-
-    #[test]
-    fn at_least_five_types_of_fruits() {
-        let mut basket = get_fruit_basket();
-        fruit_basket(&mut basket);
-        let count_fruit_kinds = basket.len();
-        assert!(count_fruit_kinds >= 5);
-    }
-
-    #[test]
-    fn greater_than_eleven_fruits() {
-        let mut basket = get_fruit_basket();
-        fruit_basket(&mut basket);
-        let count = basket.values().sum::<u32>();
-        assert!(count > 11);
-    }
-
-    #[test]
-    fn all_fruit_types_in_basket() {
-        let fruit_kinds = [
-            Fruit::Apple,
-            Fruit::Banana,
-            Fruit::Mango,
-            Fruit::Lychee,
-            Fruit::Pineapple,
-        ];
-
-        let mut basket = get_fruit_basket();
-        fruit_basket(&mut basket);
-
-        for fruit_kind in fruit_kinds {
-            let Some(amount) = basket.get(&fruit_kind) else {
-                panic!("Fruit kind {fruit_kind:?} was not found in basket");
-            };
-            assert!(*amount > 0);
-        }
-    }
-}
diff --git a/rustlings/solutions/11_hashmaps/hashmaps3.rs b/rustlings/solutions/11_hashmaps/hashmaps3.rs
deleted file mode 100644
index 485bf83..0000000
--- a/rustlings/solutions/11_hashmaps/hashmaps3.rs
+++ /dev/null
@@ -1,85 +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();
-
-        // Insert the default with zeros if a team doesn't exist yet.
-        let team_1 = scores.entry(team_1_name).or_default();
-        // Update the values.
-        team_1.goals_scored += team_1_score;
-        team_1.goals_conceded += team_2_score;
-
-        // Similarly for the second team.
-        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/solutions/12_options/options1.rs b/rustlings/solutions/12_options/options1.rs
deleted file mode 100644
index 4d615dd..0000000
--- a/rustlings/solutions/12_options/options1.rs
+++ /dev/null
@@ -1,39 +0,0 @@
-// This function returns how much icecream 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 icecream is left (value 0). Return `None` if
-// `hour_of_day` is higher than 23.
-fn maybe_icecream(hour_of_day: u16) -> Option<u16> {
-    match hour_of_day {
-        0..=21 => Some(5),
-        22..=23 => Some(0),
-        _ => None,
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn raw_value() {
-        // Using `unwrap` is fine in a test.
-        let icecreams = maybe_icecream(12).unwrap();
-
-        assert_eq!(icecreams, 5);
-    }
-
-    #[test]
-    fn check_icecream() {
-        assert_eq!(maybe_icecream(0), Some(5));
-        assert_eq!(maybe_icecream(9), Some(5));
-        assert_eq!(maybe_icecream(18), Some(5));
-        assert_eq!(maybe_icecream(22), Some(0));
-        assert_eq!(maybe_icecream(23), Some(0));
-        assert_eq!(maybe_icecream(24), None);
-        assert_eq!(maybe_icecream(25), None);
-    }
-}
diff --git a/rustlings/solutions/12_options/options2.rs b/rustlings/solutions/12_options/options2.rs
deleted file mode 100644
index 0f24665..0000000
--- a/rustlings/solutions/12_options/options2.rs
+++ /dev/null
@@ -1,37 +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);
-
-        // if-let
-        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;
-
-        // while-let with nested pattern matching
-        while let Some(Some(integer)) = optional_integers.pop() {
-            assert_eq!(integer, cursor);
-            cursor -= 1;
-        }
-
-        assert_eq!(cursor, 0);
-    }
-}
diff --git a/rustlings/solutions/12_options/options3.rs b/rustlings/solutions/12_options/options3.rs
deleted file mode 100644
index c918f71..0000000
--- a/rustlings/solutions/12_options/options3.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-#[derive(Debug)]
-struct Point {
-    x: i32,
-    y: i32,
-}
-
-fn main() {
-    let optional_point = Some(Point { x: 100, y: 200 });
-
-    // Solution 1: Matching over the `Option` (not `&Option`) but without moving
-    // out of the `Some` variant.
-    match optional_point {
-        Some(ref p) => println!("Coordinates are {},{}", p.x, p.y),
-        //   ^^^ added
-        _ => panic!("No match!"),
-    }
-
-    // Solution 2: Matching over a reference (`&Option`) by added `&` before
-    // `optional_point`.
-    match &optional_point {
-        //^ added
-        Some(p) => println!("Coordinates are {},{}", p.x, p.y),
-        _ => panic!("No match!"),
-    }
-
-    println!("{optional_point:?}");
-}
diff --git a/rustlings/solutions/13_error_handling/errors1.rs b/rustlings/solutions/13_error_handling/errors1.rs
deleted file mode 100644
index f552ca7..0000000
--- a/rustlings/solutions/13_error_handling/errors1.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-fn generate_nametag_text(name: String) -> Result<String, String> {
-    //                                    ^^^^^^         ^^^^^^
-    if name.is_empty() {
-        // `Err(String)` instead of `None`.
-        Err("Empty names aren't allowed".to_string())
-    } else {
-        // `Ok` instead of `Some`.
-        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/solutions/13_error_handling/errors2.rs b/rustlings/solutions/13_error_handling/errors2.rs
deleted file mode 100644
index f0e144e..0000000
--- a/rustlings/solutions/13_error_handling/errors2.rs
+++ /dev/null
@@ -1,58 +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;
-
-#[allow(unused_variables, clippy::question_mark)]
-fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
-    let processing_fee = 1;
-    let cost_per_item = 5;
-
-    // Added `?` to propagate the error.
-    let qty = item_quantity.parse::<i32>()?;
-    //                                    ^ added
-
-    // Equivalent to this verbose version:
-    let qty = match item_quantity.parse::<i32>() {
-        Ok(v) => v,
-        Err(e) => return Err(e),
-    };
-
-    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/solutions/13_error_handling/errors3.rs b/rustlings/solutions/13_error_handling/errors3.rs
deleted file mode 100644
index 63f4aba..0000000
--- a/rustlings/solutions/13_error_handling/errors3.rs
+++ /dev/null
@@ -1,32 +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)
-}
-
-fn main() -> Result<(), ParseIntError> {
-    //    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ added
-    let mut tokens = 100;
-    let pretend_user_input = "8";
-
-    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.");
-    }
-
-    // Added this line to return the `Ok` variant of the expected `Result`.
-    Ok(())
-}
diff --git a/rustlings/solutions/13_error_handling/errors4.rs b/rustlings/solutions/13_error_handling/errors4.rs
deleted file mode 100644
index 70c5f1c..0000000
--- a/rustlings/solutions/13_error_handling/errors4.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-use std::cmp::Ordering;
-
-#[derive(PartialEq, Debug)]
-enum CreationError {
-    Negative,
-    Zero,
-}
-
-#[derive(PartialEq, Debug)]
-struct PositiveNonzeroInteger(u64);
-
-impl PositiveNonzeroInteger {
-    fn new(value: i64) -> Result<Self, CreationError> {
-        match value.cmp(&0) {
-            Ordering::Less => Err(CreationError::Negative),
-            Ordering::Equal => Err(CreationError::Zero),
-            Ordering::Greater => 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/solutions/13_error_handling/errors5.rs b/rustlings/solutions/13_error_handling/errors5.rs
deleted file mode 100644
index c1424ee..0000000
--- a/rustlings/solutions/13_error_handling/errors5.rs
+++ /dev/null
@@ -1,54 +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)),
-        }
-    }
-}
-
-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/solutions/13_error_handling/errors6.rs b/rustlings/solutions/13_error_handling/errors6.rs
deleted file mode 100644
index ce18073..0000000
--- a/rustlings/solutions/13_error_handling/errors6.rs
+++ /dev/null
@@ -1,106 +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)
-    }
-
-    fn from_parse_int(err: ParseIntError) -> Self {
-        Self::ParseInt(err)
-    }
-}
-
-// As an alternative solution, implementing the `From` trait allows for the
-// automatic conversion from a `ParseIntError` into a `ParsePosNonzeroError`
-// using the `?` operator, without the need to call `map_err`.
-//
-// ```
-// let x: i64 = s.parse()?;
-// ```
-//
-// Traits like `From` will be dealt with in later exercises.
-impl From<ParseIntError> for ParsePosNonzeroError {
-    fn from(err: ParseIntError) -> Self {
-        ParsePosNonzeroError::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> {
-        // 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/solutions/14_generics/generics1.rs b/rustlings/solutions/14_generics/generics1.rs
deleted file mode 100644
index e2195fd..0000000
--- a/rustlings/solutions/14_generics/generics1.rs
+++ /dev/null
@@ -1,17 +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() {
-    // `u8` and `i8` can both be converted to `i16`.
-    let mut numbers: Vec<i16> = Vec::new();
-    //             ^^^^^^^^^^ added
-
-    // 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/solutions/14_generics/generics2.rs b/rustlings/solutions/14_generics/generics2.rs
deleted file mode 100644
index 14f3f7a..0000000
--- a/rustlings/solutions/14_generics/generics2.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-struct Wrapper<T> {
-    value: T,
-}
-
-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/solutions/15_traits/traits1.rs b/rustlings/solutions/15_traits/traits1.rs
deleted file mode 100644
index 790873f..0000000
--- a/rustlings/solutions/15_traits/traits1.rs
+++ /dev/null
@@ -1,32 +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 {
-    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/solutions/15_traits/traits2.rs b/rustlings/solutions/15_traits/traits2.rs
deleted file mode 100644
index 0db93e0..0000000
--- a/rustlings/solutions/15_traits/traits2.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-trait AppendBar {
-    fn append_bar(self) -> Self;
-}
-
-impl AppendBar for Vec<String> {
-    fn append_bar(mut self) -> Self {
-        //        ^^^ this is important
-        self.push(String::from("Bar"));
-        self
-    }
-}
-
-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/solutions/15_traits/traits3.rs b/rustlings/solutions/15_traits/traits3.rs
deleted file mode 100644
index 3d8ec85..0000000
--- a/rustlings/solutions/15_traits/traits3.rs
+++ /dev/null
@@ -1,36 +0,0 @@
-trait Licensed {
-    fn licensing_info(&self) -> String {
-        "Default license".to_string()
-    }
-}
-
-struct SomeSoftware {
-    version_number: i32,
-}
-
-struct OtherSoftware {
-    version_number: String,
-}
-
-impl Licensed for SomeSoftware {}
-impl Licensed for OtherSoftware {}
-
-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/solutions/15_traits/traits4.rs b/rustlings/solutions/15_traits/traits4.rs
deleted file mode 100644
index 3675b8d..0000000
--- a/rustlings/solutions/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 {}
-
-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/solutions/15_traits/traits5.rs b/rustlings/solutions/15_traits/traits5.rs
deleted file mode 100644
index 1fb426a..0000000
--- a/rustlings/solutions/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 {}
-
-fn some_func(item: impl SomeTrait + OtherTrait) -> 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/solutions/16_lifetimes/lifetimes1.rs b/rustlings/solutions/16_lifetimes/lifetimes1.rs
deleted file mode 100644
index 4f56834..0000000
--- a/rustlings/solutions/16_lifetimes/lifetimes1.rs
+++ /dev/null
@@ -1,24 +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?
-
-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/solutions/16_lifetimes/lifetimes2.rs b/rustlings/solutions/16_lifetimes/lifetimes2.rs
deleted file mode 100644
index 3ca4909..0000000
--- a/rustlings/solutions/16_lifetimes/lifetimes2.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
-    if x.len() > y.len() { x } else { y }
-}
-
-fn main() {
-    let string1 = String::from("long string is long");
-    // Solution1: You can move `strings2` out of the inner block so that it is
-    // not dropped before the print statement.
-    let string2 = String::from("xyz");
-    let result;
-    {
-        result = longest(&string1, &string2);
-    }
-    println!("The longest string is '{result}'");
-    // `string2` dropped at the end of the function.
-
-    // =========================================================================
-
-    let string1 = String::from("long string is long");
-    let result;
-    {
-        let string2 = String::from("xyz");
-        result = longest(&string1, &string2);
-        // Solution2: You can move the print statement into the inner block so
-        // that it is executed before `string2` is dropped.
-        println!("The longest string is '{result}'");
-        // `string2` dropped here (end of the inner scope).
-    }
-}
diff --git a/rustlings/solutions/16_lifetimes/lifetimes3.rs b/rustlings/solutions/16_lifetimes/lifetimes3.rs
deleted file mode 100644
index 16a5a68..0000000
--- a/rustlings/solutions/16_lifetimes/lifetimes3.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-// Lifetimes are also needed when structs hold references.
-
-struct Book<'a> {
-    //     ^^^^ added a lifetime annotation
-    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/solutions/17_tests/tests1.rs b/rustlings/solutions/17_tests/tests1.rs
deleted file mode 100644
index c52b8b1..0000000
--- a/rustlings/solutions/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 {
-    // When writing unit tests, it is common to import everything from the outer
-    // module (`super`) using a wildcard.
-    use super::*;
-
-    #[test]
-    fn you_can_assert() {
-        assert!(is_even(0));
-        assert!(!is_even(-1));
-        //      ^ You can assert `false` using the negation operator `!`.
-    }
-}
diff --git a/rustlings/solutions/17_tests/tests2.rs b/rustlings/solutions/17_tests/tests2.rs
deleted file mode 100644
index 39a0005..0000000
--- a/rustlings/solutions/17_tests/tests2.rs
+++ /dev/null
@@ -1,22 +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() {
-        assert_eq!(power_of_2(0), 1);
-        assert_eq!(power_of_2(1), 2);
-        assert_eq!(power_of_2(2), 4);
-        assert_eq!(power_of_2(3), 8);
-    }
-}
diff --git a/rustlings/solutions/17_tests/tests3.rs b/rustlings/solutions/17_tests/tests3.rs
deleted file mode 100644
index 487fdc6..0000000
--- a/rustlings/solutions/17_tests/tests3.rs
+++ /dev/null
@@ -1,45 +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() {
-        let rect = Rectangle::new(10, 20);
-        assert_eq!(rect.width, 10); // Check width
-        assert_eq!(rect.height, 20); // Check height
-    }
-
-    #[test]
-    #[should_panic] // Added this attribute to check that the test panics.
-    fn negative_width() {
-        let _rect = Rectangle::new(-10, 10);
-    }
-
-    #[test]
-    #[should_panic] // Added this attribute to check that the test panics.
-    fn negative_height() {
-        let _rect = Rectangle::new(10, -10);
-    }
-}
diff --git a/rustlings/solutions/18_iterators/iterators1.rs b/rustlings/solutions/18_iterators/iterators1.rs
deleted file mode 100644
index 93a6008..0000000
--- a/rustlings/solutions/18_iterators/iterators1.rs
+++ /dev/null
@@ -1,26 +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"];
-
-        // 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"));
-        assert_eq!(fav_fruits_iterator.next(), Some(&"avocado"));
-        assert_eq!(fav_fruits_iterator.next(), Some(&"peach"));
-        assert_eq!(fav_fruits_iterator.next(), Some(&"raspberry"));
-        assert_eq!(fav_fruits_iterator.next(), None);
-        //                                     ^^^^ reached the end
-    }
-}
diff --git a/rustlings/solutions/18_iterators/iterators2.rs b/rustlings/solutions/18_iterators/iterators2.rs
deleted file mode 100644
index db05f29..0000000
--- a/rustlings/solutions/18_iterators/iterators2.rs
+++ /dev/null
@@ -1,56 +0,0 @@
-// In this exercise, you'll learn some of the unique advantages that iterators
-// can offer.
-
-// "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() + chars.as_str(),
-    }
-}
-
-// 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> {
-    words.iter().map(|word| capitalize_first(word)).collect()
-}
-
-// 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 {
-    words.iter().map(|word| capitalize_first(word)).collect()
-}
-
-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/solutions/18_iterators/iterators3.rs b/rustlings/solutions/18_iterators/iterators3.rs
deleted file mode 100644
index 1d5d67f..0000000
--- a/rustlings/solutions/18_iterators/iterators3.rs
+++ /dev/null
@@ -1,88 +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,
-}
-
-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)
-}
-
-fn result_with_list() -> Result<Vec<i64>, DivisionError> {
-    //                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    let numbers = [27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
-    // Collects to the expected return type. Returns the first error in the
-    // division results (if one exists).
-    division_results.collect()
-}
-
-fn list_of_results() -> Vec<Result<i64, DivisionError>> {
-    //               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    let numbers = [27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
-    // Collects to the expected return type.
-    division_results.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/solutions/18_iterators/iterators4.rs b/rustlings/solutions/18_iterators/iterators4.rs
deleted file mode 100644
index 4168835..0000000
--- a/rustlings/solutions/18_iterators/iterators4.rs
+++ /dev/null
@@ -1,72 +0,0 @@
-// 3 possible solutions are presented.
-
-// With `for` loop and a mutable variable.
-fn factorial_for(num: u64) -> u64 {
-    let mut result = 1;
-
-    for x in 2..=num {
-        result *= x;
-    }
-
-    result
-}
-
-// Equivalent to `factorial_for` but shorter and without a `for` loop and
-// mutable variables.
-fn factorial_fold(num: u64) -> u64 {
-    // Case num==0: The iterator 2..=0 is empty
-    //              -> The initial value of `fold` is returned which is 1.
-    // Case num==1: The iterator 2..=1 is also empty
-    //              -> The initial value 1 is returned.
-    // Case num==2: The iterator 2..=2 contains one element
-    //              -> The initial value 1 is multiplied by 2 and the result
-    //                 is returned.
-    // Case num==3: The iterator 2..=3 contains 2 elements
-    //              -> 1 * 2 is calculated, then the result 2 is multiplied by
-    //                 the second element 3 so the result 6 is returned.
-    // And so on…
-    #[allow(clippy::unnecessary_fold)]
-    (2..=num).fold(1, |acc, x| acc * x)
-}
-
-// Equivalent to `factorial_fold` but with a built-in method that is suggested
-// by Clippy.
-fn factorial_product(num: u64) -> u64 {
-    (2..=num).product()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn factorial_of_0() {
-        assert_eq!(factorial_for(0), 1);
-        assert_eq!(factorial_fold(0), 1);
-        assert_eq!(factorial_product(0), 1);
-    }
-
-    #[test]
-    fn factorial_of_1() {
-        assert_eq!(factorial_for(1), 1);
-        assert_eq!(factorial_fold(1), 1);
-        assert_eq!(factorial_product(1), 1);
-    }
-    #[test]
-    fn factorial_of_2() {
-        assert_eq!(factorial_for(2), 2);
-        assert_eq!(factorial_fold(2), 2);
-        assert_eq!(factorial_product(2), 2);
-    }
-
-    #[test]
-    fn factorial_of_4() {
-        assert_eq!(factorial_for(4), 24);
-        assert_eq!(factorial_fold(4), 24);
-        assert_eq!(factorial_product(4), 24);
-    }
-}
diff --git a/rustlings/solutions/18_iterators/iterators5.rs b/rustlings/solutions/18_iterators/iterators5.rs
deleted file mode 100644
index 067a117..0000000
--- a/rustlings/solutions/18_iterators/iterators5.rs
+++ /dev/null
@@ -1,168 +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
-}
-
-fn count_iterator(map: &HashMap<String, Progress>, value: Progress) -> usize {
-    // `map` is a hash map with `String` keys and `Progress` values.
-    // map = { "variables1": Complete, "from_str": None, … }
-    map.values().filter(|val| **val == value).count()
-}
-
-fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
-    let mut count = 0;
-    for map in collection {
-        count += count_for(map, value);
-    }
-    count
-}
-
-fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
-    // `collection` is a slice of hash maps.
-    // collection = [{ "variables1": Complete, "from_str": None, … },
-    //               { "variables2": Complete, … }, … ]
-    collection
-        .iter()
-        .map(|map| count_iterator(map, value))
-        .sum()
-}
-
-// Equivalent to `count_collection_iterator` and `count_iterator`, iterating as
-// if the collection was a single container instead of a container of containers
-// (and more accurately, a single iterator instead of an iterator of iterators).
-fn count_collection_iterator_flat(
-    collection: &[HashMap<String, Progress>],
-    value: Progress,
-) -> usize {
-    // `collection` is a slice of hash maps.
-    // collection = [{ "variables1": Complete, "from_str": None, … },
-    //               { "variables2": Complete, … }, … ]
-    collection
-        .iter()
-        .flat_map(HashMap::values) // or just `.flatten()` when wanting the default iterator (`HashMap::iter`)
-        .filter(|val| **val == value)
-        .count()
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use Progress::*;
-
-    fn get_map() -> HashMap<String, 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>> {
-        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, Complete), 3);
-    }
-
-    #[test]
-    fn count_some() {
-        let map = get_map();
-        assert_eq!(count_iterator(&map, Some), 1);
-    }
-
-    #[test]
-    fn count_none() {
-        let map = get_map();
-        assert_eq!(count_iterator(&map, None), 2);
-    }
-
-    #[test]
-    fn count_complete_equals_for() {
-        let map = get_map();
-        let progress_states = [Complete, Some, 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, Complete), 6);
-        assert_eq!(count_collection_iterator_flat(&collection, Complete), 6);
-    }
-
-    #[test]
-    fn count_collection_some() {
-        let collection = get_vec_map();
-        assert_eq!(count_collection_iterator(&collection, Some), 1);
-        assert_eq!(count_collection_iterator_flat(&collection, Some), 1);
-    }
-
-    #[test]
-    fn count_collection_none() {
-        let collection = get_vec_map();
-        assert_eq!(count_collection_iterator(&collection, None), 4);
-        assert_eq!(count_collection_iterator_flat(&collection, None), 4);
-    }
-
-    #[test]
-    fn count_collection_equals_for() {
-        let collection = get_vec_map();
-        let progress_states = [Complete, Some, None];
-
-        for progress_state in progress_states {
-            assert_eq!(
-                count_collection_for(&collection, progress_state),
-                count_collection_iterator(&collection, progress_state),
-            );
-            assert_eq!(
-                count_collection_for(&collection, progress_state),
-                count_collection_iterator_flat(&collection, progress_state),
-            );
-        }
-    }
-}
diff --git a/rustlings/solutions/19_smart_pointers/arc1.rs b/rustlings/solutions/19_smart_pointers/arc1.rs
deleted file mode 100644
index bd76189..0000000
--- a/rustlings/solutions/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();
-
-    let shared_numbers = Arc::new(numbers);
-    //                   ^^^^^^^^^^^^^^^^^
-
-    let mut join_handles = Vec::new();
-
-    for offset in 0..8 {
-        let child_numbers = Arc::clone(&shared_numbers);
-        //                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-        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/solutions/19_smart_pointers/box1.rs b/rustlings/solutions/19_smart_pointers/box1.rs
deleted file mode 100644
index 189cc56..0000000
--- a/rustlings/solutions/19_smart_pointers/box1.rs
+++ /dev/null
@@ -1,47 +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`.
-
-#[derive(PartialEq, Debug)]
-enum List {
-    Cons(i32, Box<List>),
-    Nil,
-}
-
-fn create_empty_list() -> List {
-    List::Nil
-}
-
-fn create_non_empty_list() -> List {
-    List::Cons(42, 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/solutions/19_smart_pointers/cow1.rs b/rustlings/solutions/19_smart_pointers/cow1.rs
deleted file mode 100644
index 461143b..0000000
--- a/rustlings/solutions/19_smart_pointers/cow1.rs
+++ /dev/null
@@ -1,69 +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/solutions/19_smart_pointers/rc1.rs b/rustlings/solutions/19_smart_pointers/rc1.rs
deleted file mode 100644
index edf40eb..0000000
--- a/rustlings/solutions/19_smart_pointers/rc1.rs
+++ /dev/null
@@ -1,102 +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();
-
-        let saturn = Planet::Saturn(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
-        saturn.details();
-
-        let uranus = Planet::Uranus(Rc::clone(&sun));
-        println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
-        uranus.details();
-
-        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
-
-        drop(earth);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
-
-        drop(venus);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
-
-        drop(mercury);
-        println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
-
-        assert_eq!(Rc::strong_count(&sun), 1);
-    }
-}
diff --git a/rustlings/solutions/20_threads/threads1.rs b/rustlings/solutions/20_threads/threads1.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/20_threads/threads1.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/20_threads/threads2.rs b/rustlings/solutions/20_threads/threads2.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/20_threads/threads2.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/20_threads/threads3.rs b/rustlings/solutions/20_threads/threads3.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/20_threads/threads3.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/21_macros/macros1.rs b/rustlings/solutions/21_macros/macros1.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/21_macros/macros1.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/21_macros/macros2.rs b/rustlings/solutions/21_macros/macros2.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/21_macros/macros2.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/21_macros/macros3.rs b/rustlings/solutions/21_macros/macros3.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/21_macros/macros3.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/21_macros/macros4.rs b/rustlings/solutions/21_macros/macros4.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/21_macros/macros4.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/22_clippy/clippy1.rs b/rustlings/solutions/22_clippy/clippy1.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/22_clippy/clippy1.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/22_clippy/clippy2.rs b/rustlings/solutions/22_clippy/clippy2.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/22_clippy/clippy2.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/22_clippy/clippy3.rs b/rustlings/solutions/22_clippy/clippy3.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/22_clippy/clippy3.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/23_conversions/as_ref_mut.rs b/rustlings/solutions/23_conversions/as_ref_mut.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/23_conversions/as_ref_mut.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/23_conversions/from_into.rs b/rustlings/solutions/23_conversions/from_into.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/23_conversions/from_into.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/23_conversions/from_str.rs b/rustlings/solutions/23_conversions/from_str.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/23_conversions/from_str.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/23_conversions/try_from_into.rs b/rustlings/solutions/23_conversions/try_from_into.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/23_conversions/try_from_into.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/23_conversions/using_as.rs b/rustlings/solutions/23_conversions/using_as.rs
deleted file mode 100644
index dcf2377..0000000
--- a/rustlings/solutions/23_conversions/using_as.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
-}
diff --git a/rustlings/solutions/README.md b/rustlings/solutions/README.md
deleted file mode 100644
index 5b5176b..0000000
--- a/rustlings/solutions/README.md
+++ /dev/null
@@ -1,6 +0,0 @@
-# Official Rustlings solutions
-
-Before you finish an exercise, its solution file will only contain an empty `main` function.
-The content of this file will be automatically replaced by the actual solution once you finish the exercise.
-
-Note that these solutions are often only _one possibility_ to solve an exercise.
diff --git a/rustlings/solutions/quizzes/quiz1.rs b/rustlings/solutions/quizzes/quiz1.rs
deleted file mode 100644
index 5503c8c..0000000
--- a/rustlings/solutions/quizzes/quiz1.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-// 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_apples: u64) -> u64 {
-    if n_apples > 40 {
-        n_apples
-    } else {
-        2 * n_apples
-    }
-}
-
-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/solutions/quizzes/quiz2.rs b/rustlings/solutions/quizzes/quiz2.rs
deleted file mode 100644
index 8b073b1..0000000
--- a/rustlings/solutions/quizzes/quiz2.rs
+++ /dev/null
@@ -1,90 +0,0 @@
-// 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;
-
-    // The solution with a loop. Check out `transformer_iter` for a version
-    // with iterators.
-    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
-        let mut output = Vec::new();
-
-        for (string, command) in input {
-            // Create the new string.
-            let new_string = match command {
-                Command::Uppercase => string.to_uppercase(),
-                Command::Trim => string.trim().to_string(),
-                Command::Append(n) => string + &"bar".repeat(n),
-            };
-
-            // Push the new string to the output vector.
-            output.push(new_string);
-        }
-
-        output
-    }
-
-    // Equivalent to `transform` but uses an iterator instead of a loop for
-    // comparison. Don't worry, we will practice iterators later ;)
-    pub fn transformer_iter(input: Vec<(String, Command)>) -> Vec<String> {
-        input
-            .into_iter()
-            .map(|(string, command)| match command {
-                Command::Uppercase => string.to_uppercase(),
-                Command::Trim => string.trim().to_string(),
-                Command::Append(n) => string + &"bar".repeat(n),
-            })
-            .collect()
-    }
-}
-
-fn main() {
-    // You can optionally experiment here.
-}
-
-#[cfg(test)]
-mod tests {
-    // Import `transformer`.
-    use super::my_module::transformer;
-
-    use super::Command;
-    use super::my_module::transformer_iter;
-
-    #[test]
-    fn it_works() {
-        for transformer in [transformer, transformer_iter] {
-            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/solutions/quizzes/quiz3.rs b/rustlings/solutions/quizzes/quiz3.rs
deleted file mode 100644
index 7b91278..0000000
--- a/rustlings/solutions/quizzes/quiz3.rs
+++ /dev/null
@@ -1,65 +0,0 @@
-// 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.
-
-use std::fmt::Display;
-
-// Make the struct generic over `T`.
-struct ReportCard<T> {
-    //           ^^^
-    grade: T,
-    //     ^
-    student_name: String,
-    student_age: u8,
-}
-
-// To be able to print the grade, it has to implement the `Display` trait.
-impl<T: Display> ReportCard<T> {
-    //  ^^^^^^^ require that `T` implements `Display`.
-    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+",
-        );
-    }
-}