Perfect Numbers in Scala
Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for natural numbers.
exercism fetch scala perfect-numbers
The Greek mathematician Nicomachus devised a classification scheme for natural numbers, identifying each as belonging uniquely to the categories of perfect, abundant, or deficient based on their aliquot sum. The aliquot sum is defined as the sum of the factors of a number not including the number itself. For example, the aliquot sum of 15 is (1 + 3 + 5) = 9
Perfect: aliquot sum = number
- 6 is a perfect number because (1 + 2 + 3) = 6
- 28 is a perfect number because (1 + 2 + 4 + 7 + 14) = 28
Abundant: aliquot sum > number
- 12 is an abundant number because (1 + 2 + 3 + 4 + 6) = 16
- 24 is an abundant number because (1 + 2 + 3 + 4 + 6 + 8 + 12) = 36
Deficient: aliquot sum < number
- 8 is a deficient number because (1 + 2 + 4) = 7
- Prime numbers are deficient
Implement a way to determine whether a given number is perfect. Depending on your language track, you may also need to implement a way to determine whether a given number is abundant or deficient.
The Scala exercises assume an SBT project scheme. The exercise solution source should be placed within the exercise directory/src/main/scala. The exercise unit tests can be found within the exercise directory/src/test/scala.
To run the tests simply run the command
sbt test in the exercise directory.
For more detailed info about the Scala track see the help page.
Taken from Chapter 2 of Functional Thinking by Neal Ford. http://shop.oreilly.com/product/0636920029687.do
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.