fizzbuzz2.exs

defmodule S do
  def fizzbuzz(n), do: fb(3, 5, 1, n, [])

  def fb(_fizz, _buzz, i, i, r), do: r |> Enum.reverse

  def fb(i, i, i, j, r) do
    fb(i+3, i+5, i+1, j, ["FizzBuzz"|r])
  end
  def fb(i, buzz, i, j, r) do
    fb(i+3, buzz, i+1, j, ["Fizz"|r])
  end
  def fb(fizz, i, i, j, r) do
    fb(fizz, i+5, i+1, j, ["Buzz"|r])
  end
  def fb(fizz, buzz, i, j, r) do
    fb(fizz, buzz, i+1, j, [i|r])
  end
end