new challenge ownership

challenges.json re-order

challenges/challenges.json

@@ -167,6 +167,66 @@
     "created_at": "2024-06-12T00:00:00Z",
     "updated_at": "2024-06-12T00:00:00Z"
   },
+  {
+    "id": 10,
+    "title": "Basic If-Else Statements",
+    "slug": "if-else",
+    "short_description": "Learn how to use if-else statements in Rust to control the flow of your program.",
+    "language": "RUST",
+    "difficulty": "EASY",
+    "track": "CONTROL_FLOW",
+    "tags": ["control flow", "if-else"],
+    "created_at": "2024-06-01T00:00:00Z",
+    "updated_at": "2024-06-01T00:00:00Z"
+  },
+  {
+    "id": 11,
+    "title": "Sum of Even Numbers",
+    "slug": "sum-of-even-numbers",
+    "short_description": "Implement a function to sum even numbers in a given range using a for loop.",
+    "language": "RUST",
+    "difficulty": "EASY",
+    "track": "CONTROL_FLOW",
+    "tags": ["for-loop", "iteration", "range"],
+    "created_at": "2024-06-02T00:00:00Z",
+    "updated_at": "2024-06-02T00:00:00Z"
+  },
+  {
+    "id": 12,
+    "title": "Countdown",
+    "slug": "countdown",
+    "short_description": "Implement a countdown timer using a while loop in Rust.",
+    "language": "RUST",
+    "difficulty": "EASY",
+    "track": "CONTROL_FLOW",
+    "tags": ["while", "loop", "control flow"],
+    "created_at": "2024-06-02T00:00:00Z",
+    "updated_at": "2024-06-02T00:00:00Z"
+  },
+  {
+    "id": 13,
+    "title": "Weekday from Number",
+    "slug": "weekday-from-number",
+    "short_description": "Use Rust's pattern matching to determine the weekday given its number.",
+    "language": "RUST",
+    "difficulty": "EASY",
+    "track": "CONTROL_FLOW",
+    "tags": ["pattern matching", "match", "control flow"],
+    "created_at": "2024-06-02T00:00:00Z",
+    "updated_at": "2024-06-02T00:00:00Z"
+  },
+  {
+    "id": 34,
+    "title": "Ownership",
+    "slug": "ownership",
+    "short_description": "Understand and implement Rust's ownership model.",
+    "language": "RUST",
+    "difficulty": "EASY",
+    "track": "RUST_BASICS",
+    "tags": ["ownership", "borrowing", "lifetimes"],
+    "created_at": "2024-06-13T00:00:00Z",
+    "updated_at": "2024-06-13T00:00:00Z"
+  },
   {
     "id": 2,
     "title": "Character counting string",
@@ -251,54 +311,6 @@
     "created_at": "2024-05-06T00:00:00Z",
     "updated_at": "2024-05-06T00:00:00Z"
   },
-  {
-    "id": 10,
-    "title": "Basic If-Else Statements",
-    "slug": "if-else",
-    "short_description": "Learn how to use if-else statements in Rust to control the flow of your program.",
-    "language": "RUST",
-    "difficulty": "EASY",
-    "track": "CONTROL_FLOW",
-    "tags": ["control flow", "if-else"],
-    "created_at": "2024-06-01T00:00:00Z",
-    "updated_at": "2024-06-01T00:00:00Z"
-  },
-  {
-    "id": 11,
-    "title": "Sum of Even Numbers",
-    "slug": "sum-of-even-numbers",
-    "short_description": "Implement a function to sum even numbers in a given range using a for loop.",
-    "language": "RUST",
-    "difficulty": "EASY",
-    "track": "CONTROL_FLOW",
-    "tags": ["for-loop", "iteration", "range"],
-    "created_at": "2024-06-02T00:00:00Z",
-    "updated_at": "2024-06-02T00:00:00Z"
-  },
-  {
-    "id": 12,
-    "title": "Countdown",
-    "slug": "countdown",
-    "short_description": "Implement a countdown timer using a while loop in Rust.",
-    "language": "RUST",
-    "difficulty": "EASY",
-    "track": "CONTROL_FLOW",
-    "tags": ["while", "loop", "control flow"],
-    "created_at": "2024-06-02T00:00:00Z",
-    "updated_at": "2024-06-02T00:00:00Z"
-  },
-  {
-    "id": 13,
-    "title": "Weekday from Number",
-    "slug": "weekday-from-number",
-    "short_description": "Use Rust's pattern matching to determine the weekday given its number.",
-    "language": "RUST",
-    "difficulty": "EASY",
-    "track": "CONTROL_FLOW",
-    "tags": [],
-    "created_at": "2024-06-02T00:00:00Z",
-    "updated_at": "2024-06-02T00:00:00Z"
-  },
   {
     "id": 14,
     "title": "Is Prime",

challenges/ownership/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "ownership"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

challenges/ownership/description.md

@@ -0,0 +1,62 @@
+Rust's ownership model is one of its most unique and powerful features, ensuring **memory safety** without needing a garbage collector. Ownership in Rust is governed by a set of rules that the compiler checks at compile time. Understanding these rules is crucial for writing efficient and safe Rust code.
+
+## Ownership Basics
+
+In Rust, each value has a variable that's called its **owner**. There can only be one owner at a time, and when the owner goes out of scope, the value is dropped. Here are the basic rules of ownership:
+
+1. Each value in Rust has a variable that's called its **owner**.
+2. There can only be **one owner at a time**.
+3. When the owner goes out of scope, the value will be **dropped** (no longer valid).
+
+### Example
+
+```rust
+{
+    let s = String::from("hello"); // s is the owner of the String
+} // s goes out of scope and "hello" is dropped
+```
+
+## Borrowing
+
+Rust allows you to create **references** to a value, which lets you access it without taking ownership. This is called **borrowing**. Borrowing can be **immutable** or **mutable**.
+
+### Immutable References
+
+You can create multiple **immutable references** to a value, but you cannot have a mutable reference while immutable references exist. This allows you to read from the value without changing it.
+
+## Example
+
+```rust
+fn main() {
+    let s1 = String::from("hello");
+
+    let len = calculate_length(&s1); // borrow s1 as immutable
+    println!("The length of '{}' is {}.", s1, len);
+}
+
+fn calculate_length(s: &String) -> usize { // s is an immutable reference to a String
+    s.len()
+} // s goes out of scope here, but since it does not have ownership of the String, nothing happens
+```
+
+## Challenge
+
+In this challenge, you will create a function `calculate_length` that takes an immutable reference to a `String`, calculates its length, and returns the length.
+
+The task is designed to help you understand the concepts of ownership and immutable borrowing in Rust.
+
+## Requirements
+
+- The `calculate_length` function should take **an immutable reference** to the input `String` and return its length.
+
+## Example
+
+```rust
+let s1 = String::from("hello");
+let len = calculate_length(&s1);
+assert_eq!(len, 5);
+```
+
+## Hints
+
+- The `String` type in Rust has a method `len()` which returns its length.

challenges/ownership/src/lib.rs

@@ -0,0 +1,3 @@
+pub fn calculate_length(s: &String) -> usize {
+    s.len()
+}

challenges/ownership/src/starter.rs

@@ -0,0 +1,3 @@
+pub fn calculate_length(s: &String) -> usize {
+    // Your code here...
+}

challenges/ownership/tests/tests.rs

@@ -0,0 +1,37 @@
+#[cfg(test)]
+mod tests {
+    use ownership::calculate_length;
+
+    #[test]
+    fn test_calculate_length() {
+        assert_eq!(
+            calculate_length(&String::from("hello")),
+            5,
+            "Expected the length of 'hello' to be 5"
+        );
+
+        assert_eq!(
+            calculate_length(&String::from("world")),
+            5,
+            "Expected the length of 'world' to be 5"
+        );
+
+        assert_eq!(
+            calculate_length(&String::from("hello world")),
+            11,
+            "Expected the length of 'hello world' to be 11"
+        );
+
+        assert_eq!(
+            calculate_length(&String::from("hello world!")),
+            12,
+            "Expected the length of 'hello world!' to be 12"
+        );
+
+        assert_eq!(
+            calculate_length(&String::from("I'm a rust developer, and I love it!")),
+            36,
+            "Expected the text to be 39 characters long"
+        );
+    }
+}