43 lines
1.4 KiB
Markdown
43 lines
1.4 KiB
Markdown
|
# Perfect Numbers
|
||
|
|
|
||
|
|
The Greek mathematician Nicomachus devised a classification scheme for natural numbers.
|
||
|
|
|
||
|
|
The Greek mathematican Nicomachus devised a classification scheme for
|
||
|
|
natural numbers, identifying each as belonging uniquely to the
|
||
|
|
categories of _abundant_, _perfect_, or _deficient_. A perfect number
|
||
|
|
equals the sum of its positive divisors — the pairs of numbers whose
|
||
|
|
product yields the target number, excluding the number itself.
|
||
|
|
|
||
|
|
- Perfect: Sum of factors = number
|
||
|
|
- Abundant: Sum of factors > number
|
||
|
|
- Deficient: Sum of factors < number
|
||
|
|
|
||
|
|
The Aliquot sum is defined as the sum of the factors of a number not
|
||
|
|
including the number itself.
|
||
|
|
|
||
|
|
## Examples
|
||
|
|
|
||
|
|
- 6 is a perfect number because its divisors are 1, 2, 3 and 6 = 1 + 2 +
|
||
|
|
3.
|
||
|
|
- 28 is perfect number because 28 = 1 + 2 + 4 + 7 + 14.
|
||
|
|
- Prime numbers 7, 13, etc are Deficient by the Nicomachus
|
||
|
|
classification.
|
||
|
|
|
||
|
|
To run the tests simply run the command `go test` in the exercise directory.
|
||
|
|
|
||
|
|
If the test suite contains benchmarks, you can run these with the `-bench`
|
||
|
|
flag:
|
||
|
|
|
||
|
|
go test -bench .
|
||
|
|
|
||
|
|
For more detailed info about the Go track see the [help
|
||
|
|
page](http://exercism.io/languages/go).
|
||
|
|
|
||
|
|
## Source
|
||
|
|
|
||
|
|
Taken from Chapter 2 of Functional Thinking by Neal Ford. [http://shop.oreilly.com/product/0636920029687.do](http://shop.oreilly.com/product/0636920029687.do)
|
||
|
|
|
||
|
|
## Submitting Incomplete Problems
|
||
|
|
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|
||
|
|
|