Chapter 14, Silver Challenge Solution

Swift Programming (3rd Edition) 14. Enumerations
1 
import Cocoa

enum ShapeDimensions {
    // point has no associated value - it is dimensionless
    case point
    
    // square's associated value is the length of one side
    case square(side: Double)
    
    // rectangle's associated value defines its width and height
    case rectangle(width: Double, height: Double)
    
    // triangle's associated value defines its width and height
    case triangle(width: Double, height: Double)
    
    func area() -> Double {
        switch self {
        case .point:
            return 0
            
        case let .square(side: side):
            return side * side
            
        case let .rectangle(width: w, height: h):
            return w * h
            
        case let .triangle(width: w, height: h):
            return (w * h) / 2.0
            
        }
    }
    
    func perimeter() -> Double {
        switch self {
        case .point:
            return 0
            
        case let .square(side: side):
            return 4 * side
            
        case let .rectangle(width: w, height: h):
            return (2 * w) + (2 * h)
            
        case let .triangle(width: w, height: h):
            return (w + h + sqrt(pow(w, 2) + pow(h, 2)))
            
        }
    }
}

let squareShape = ShapeDimensions.square(side: 10.0)
let rectangleShape = ShapeDimensions.rectangle(width: 5.0, height: 10.0)
let pointShape = ShapeDimensions.point
let triangleShape = ShapeDimensions.triangle(width: 5.0, height: 10.0)

print("square's area = \(squareShape.area())")
print("rectangle's area = \(rectangleShape.area())")
print("point's area = \(pointShape.area())")
print("triangle's area = \(triangleShape.area())")

print("square's perimeter = \(squareShape.perimeter())")
print("rectangle's perimeter = \(rectangleShape.perimeter())")
print("point's perimeter = \(pointShape.perimeter())")
print("triangle's perimeter = \(triangleShape.perimeter())")

Edit: Third time is the charm?

2

My solution is a bit simpler.

enum ShapeDimensions {

case point

case square(side: Double)

case rectangle(width: Double, height: Double)

///Silver Challenge

case rightTriangle(height: Double, base: Double, hypotenus: Double)

func area() -> Double {

    switch self {

    case .point:

        return 0

    case let .square(side: side):

        return side * 2

    case let .rectangle(width: width, height: height):

        return width * height

    case let .rightTriangle(height: a, base: b, hypotenus: c):

        return (a * b) / 2

    }

}

func perimeter() -> Double {

    switch self {

    case .point:

        return 0

    case let .square(side: side):

        return side * 4

    case let .rectangle(width: width, height: height):

        return (width * 2) + (height * 2)

    case let .rightTriangle(height: a, base: b, hypotenuse: c):

        return a + b + c

    }

   }
}

var rightTrianglePerimeter = rightTriangleShape.perimeter()

print(“Right Triangle’s perimeter \(rightTrianglePerimeter)”)