Problem Statement

A Narcissistic Number is a number which is the sum of its own digits, each raised to the power of the number of digits.


describe Narcissistic do
  it 'returns true for one' do
    Narcissistic.(1).must_equal true

  it 'returns false for for 22' do
    Narcissistic.(22).must_equal false

  it 'returns true for 153' do
    Narcissistic.(153).must_equal true

  it 'returns true for 1634' do
    Narcissistic.(1634).must_equal true


module Narcissistic
  extend self

  def call(num)
    numbers = num.to_s.chars
      inject(0) { |sum, number| sum += number**numbers.size } == num

What did I learn about this kata?

For starters; I think that one of the things that I learned was related to idiomatic Ruby instead of anything else; it is obvious that this problem is very simple. So What ocurrs to me was just to switch things up a little bit not from the complexity stand point just from the idiomatic stand point.

As Ruby have the same notion as Perl does TMTOWTDI I decided to just switch some small details of the implementation. For instance: { |n| n.to_i**numbers.size }.inject(:+)

I feel this looks more concise at least to me; actually have to give it a little bit more of thought; anyways that was the Kata for today. If you want to try to do the same and find problems to solve on a daily or weekly basics just go ahead to (Codewars)[] great resource for keep getting better at programming. Happy hacking!