Week3 submission

week3/Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+rand = "0.8.5"

week3/src/lib.rs

@@ -1 +1,67 @@
+use std::any::TypeId;
 
+enum Shape {
+    Circle { radius: f64 },
+    Square { length: f64 },
+    Rectangle { width: f64, height: f64 },
+}
+
+fn area(shape: &Shape) -> f64 {
+    match shape {
+        Shape::Circle { radius } => radius * radius * std::f64::consts::PI,
+        Shape::Square { length } => length * length,
+        Shape::Rectangle { width, height } => width * height,
+    }
+}
+
+#[test]
+fn test_shape_areas() {
+    assert_eq!(area(&Shape::Circle { radius: 1.0 }), std::f64::consts::PI);
+    assert_eq!(area(&Shape::Square { length: 2.0 }), 4.0);
+    assert_eq!(
+        area(&Shape::Rectangle {
+            width: 3.0,
+            height: 8.0
+        }),
+        24.0
+    );
+}
+
+fn random_shape() -> Shape {
+    match rand::random::<i32>() % 3 {
+        0 => Shape::Circle {
+            radius: rand::random(),
+        },
+        1 => Shape::Square {
+            length: rand::random(),
+        },
+        _ => Shape::Rectangle {
+            width: rand::random(),
+            height: rand::random(),
+        },
+    }
+}
+
+fn circle_area(shape: &Shape) -> Option<f64> {
+    if let Shape::Circle { .. } = shape {
+        Option::Some(area(shape))
+    } else {
+        Option::None
+    }
+}
+
+#[test]
+fn test_circle_area() {
+    assert_eq!(
+        circle_area(&Shape::Circle { radius: (1.0) }),
+        Some(std::f64::consts::PI)
+    );
+    assert_eq!(
+        circle_area(&Shape::Rectangle {
+            width: 1.0,
+            height: 1.0
+        }),
+        None
+    );
+    assert_eq!(circle_area(&Shape::Square { length: 1.0 }), None);
+}