stevedowney

defmodule ProjectEuler.Problem4a do
  
  @moduledoc """
  A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.

  Find the largest palindrome made from the product of two 3-digit numbers.
  
      iex> ProjectEuler.Problem4a.solve
      906609
  """

stevedowney

defmodule Fib do

  # Naive implementation
  
  def fib(0), do: 0
  def fib(1), do: 1
  
  def fib(n)
    when is_integer(n) and n > 1,
    do: fib(n-1) + fib(n-2)

stevedowney

defmodule RomanNumeral do
  @mapping [
    {1000, "M"},
    {900, "CM"},
    {500, "D"},
    {400, "CD"},
    {100, "C"},
    {90, "XC"},
    {50, "L"},
    {40, "XL"},