armstrong_number

elixir/armstrong-numbers/lib/armstrong_number.ex

@@ -0,0 +1,13 @@
+defmodule ArmstrongNumber do
+  @moduledoc """
+  Provides a way to validate whether or not a number is an Armstrong number
+  """
+
+  @spec valid?(integer) :: boolean
+  def valid?(number) do
+    digits = Integer.digits(number)
+    power = length(digits)
+
+    Enum.reduce(digits, 0, &(&1 ** power + &2)) == number
+  end
+end