20160315_zndco_kiyoshi.exs

defmodule Znd do
  @z "ズン"
  @d "ドコ"
  @k "キ・ヨ・シ"

  def kiyoshi, do: [] |> kiy

  defp kiy(zd) when zd == [@z, @z, @z, @z, @d], do: [zd|[@k]] |> Enum.join
  defp kiy(zd) when length(zd) > 5, do: tl(zd) |> kiy
  defp kiy(zd), do: [zd|[Enum.random([@z, @d])]] |> List.flatten |> kiy
end

defmodule Znd do
  @z "ズン"
  @d "ドコ"
  @k "キ・ヨ・シ"

  def kiyoshi, do: [] |> kiy

  defp kiy(zd) when zd == [@d, @z, @z, @z, @z], do: [@k|zd] |> Enum.reverse |> Enum.join
  defp kiy(zd) when length(zd) > 5 do
    {h, t} = zd |> Enum.split(5)
    t |> List.to_string |> IO.puts
    h |> kiy
  end
  defp kiy(zd), do: [Enum.random([@z, @d])|zd] |> kiy
end