coding rust 17-18

exercises/17_tests/tests1.rs

@@ -13,11 +13,12 @@ fn main() {
 mod tests {
     // TODO: Import `is_even`. You can use a wildcard to import everything in
     // the outer module.
+    use super::is_even;
 
     #[test]
     fn you_can_assert() {
         // TODO: Test the function `is_even` with some values.
-        assert!();
-        assert!();
+        assert!(is_even(10));
+        assert!(!is_even(11));
     }
 }

exercises/17_tests/tests2.rs

@@ -14,10 +14,11 @@ mod tests {
 
     #[test]
     fn you_can_assert_eq() {
+
         // TODO: Test the function `power_of_2` with some values.
-        assert_eq!();
-        assert_eq!();
-        assert_eq!();
-        assert_eq!();
+        assert_eq!(power_of_2(2), 4);
+        assert_eq!(power_of_2(3), 8);
+        assert_eq!(power_of_2(4), 16);
+        assert_eq!(power_of_2(8), 256);
     }
 }

exercises/17_tests/tests3.rs

@@ -29,13 +29,14 @@ mod tests {
         // TODO: This test should check if the rectangle has the size that we
         // pass to its constructor.
         let rect = Rectangle::new(10, 20);
-        assert_eq!(todo!(), 10); // Check width
-        assert_eq!(todo!(), 20); // Check height
+        assert_eq!(rect.width, 10); // Check width
+        assert_eq!(rect.height, 20); // Check height
     }
 
     // TODO: This test should check if the program panics when we try to create
     // a rectangle with negative width.
     #[test]
+    #[should_panic]
     fn negative_width() {
         let _rect = Rectangle::new(-10, 10);
     }
@@ -43,6 +44,7 @@ mod tests {
     // TODO: This test should check if the program panics when we try to create
     // a rectangle with negative height.
     #[test]
+    #[should_panic]
     fn negative_height() {
         let _rect = Rectangle::new(10, -10);
     }

exercises/18_iterators/iterators1.rs

@@ -13,13 +13,13 @@ mod tests {
         let my_fav_fruits = ["banana", "custard apple", "avocado", "peach", "raspberry"];
 
         // TODO: Create an iterator over the array.
-        let mut fav_fruits_iterator = todo!();
+        let mut fav_fruits_iterator = my_fav_fruits.iter();
 
         assert_eq!(fav_fruits_iterator.next(), Some(&"banana"));
-        assert_eq!(fav_fruits_iterator.next(), todo!()); // TODO: Replace `todo!()`
+        assert_eq!(fav_fruits_iterator.next(), Some(&"custard apple")); // TODO: Replace `todo!()`
         assert_eq!(fav_fruits_iterator.next(), Some(&"avocado"));
-        assert_eq!(fav_fruits_iterator.next(), todo!()); // TODO: Replace `todo!()`
+        assert_eq!(fav_fruits_iterator.next(), Some(&"peach")); // TODO: Replace `todo!()`
         assert_eq!(fav_fruits_iterator.next(), Some(&"raspberry"));
-        assert_eq!(fav_fruits_iterator.next(), todo!()); // TODO: Replace `todo!()`
+        assert_eq!(fav_fruits_iterator.next(), None); // TODO: Replace `todo!()`
     }
 }

exercises/18_iterators/iterators2.rs

@@ -7,7 +7,7 @@ fn capitalize_first(input: &str) -> String {
     let mut chars = input.chars();
     match chars.next() {
         None => String::new(),
-        Some(first) => todo!(),
+        Some(first) => first.to_uppercase().collect::<String>() + chars.as_str(),
     }
 }
 
@@ -15,14 +15,20 @@ fn capitalize_first(input: &str) -> String {
 // Return a vector of strings.
 // ["hello", "world"] -> ["Hello", "World"]
 fn capitalize_words_vector(words: &[&str]) -> Vec<String> {
-    // ???
+    words.iter().map(|x| {
+        capitalize_first(x)
+    }).collect()
 }
 
 // TODO: Apply the `capitalize_first` function again to a slice of string
 // slices. Return a single string.
 // ["hello", " ", "world"] -> "Hello World"
 fn capitalize_words_string(words: &[&str]) -> String {
-    // ???
+    let mut string = String::new();
+    words.iter().for_each(|x| {
+        string.push_str(capitalize_first(x).as_str());
+    });
+    string
 }
 
 fn main() {

exercises/18_iterators/iterators3.rs

@@ -7,21 +7,27 @@ enum DivisionError {
 // TODO: Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
 // Otherwise, return a suitable error.
 fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
-    todo!();
+    if b == 0 {
+        Err(DivisionError::DivideByZero)
+    } else if a % b == 0 {
+        Ok(a / b)
+    } else {
+        Err(DivisionError::NotDivisible)
+    }
 }
 
 // TODO: Add the correct return type and complete the function body.
 // Desired output: `Ok([1, 11, 1426, 3])`
-fn result_with_list() {
+fn result_with_list() -> Result<Vec<i32>, DivisionError> {
     let numbers = [27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    numbers.into_iter().map(|n| divide(n, 27)).collect()
 }
 
 // TODO: Add the correct return type and complete the function body.
 // Desired output: `[Ok(1), Ok(11), Ok(1426), Ok(3)]`
-fn list_of_results() {
+fn list_of_results() -> Vec<Result<i32, DivisionError>> {
     let numbers = [27, 297, 38502, 81];
-    let division_results = numbers.into_iter().map(|n| divide(n, 27));
+    numbers.into_iter().map(|n| divide(n, 27)).collect()
 }
 
 fn main() {

exercises/18_iterators/iterators4.rs

@@ -7,6 +7,7 @@ fn factorial(num: u64) -> u64 {
     // - additional variables
     // For an extra challenge, don't use:
     // - recursion
+    (1..=num).product()
 }
 
 fn main() {

exercises/18_iterators/iterators5.rs

@@ -28,6 +28,7 @@ fn count_for(map: &HashMap<String, Progress>, value: Progress) -> usize {
 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.iter().filter(|x| { x.1 == &value }).count()
 }
 
 fn count_collection_for(collection: &[HashMap<String, Progress>], value: Progress) -> usize {
@@ -48,6 +49,7 @@ fn count_collection_iterator(collection: &[HashMap<String, Progress>], value: Pr
     // `collection` is a slice of hash maps.
     // collection = [{ "variables1": Complete, "from_str": None, … },
     //               { "variables2": Complete, … }, … ]
+    collection.iter().map(|x| { count_iterator(x, value) }).sum()
 }
 
 fn main() {