EvenOdd

defmodule Evenodd do

  def start() do even_odd_sort([],[]) |>  print_list end
  defp print_list(list) do Enum.map list, &(IO.puts(&1))  end

  defp even_odd_sort(odd,even) do
        case getline do
          { :done, :done } -> make_new_list(even,odd)
          { line, :odd}  -> even_odd_sort( [line] ++ odd, even)
          { line, :even}  -> even_odd_sort( odd,[line] ++ even)
        end
  end

  defp make_new_list(even,odd) do combineList(Enum.sort(even),Enum.sort(odd),:do_even)  end

  defp combineList([],odd,_) do odd end
  defp combineList(even,[],_) do even end
  defp combineList(even,[ head | tail ],:do_odd) do [head] ++ combineList(even,tail,:do_even) end
  defp combineList([ head | tail ], odd,:do_even) do  [head] ++ combineList(tail,odd,:do_odd) end

  defp getline() do IO.read(:line) |> remove_new_line |> String.to_integer |>  process_line end
  defp remove_new_line(str), do: String.replace(str, ~r/\n/, "")

  defp process_line(0) do {:done, :done } end
  defp process_line(line) do
      cond do
         rem(line,2) != 0 && line != 0  -> {line, :odd}
         true -> {line , :even }
      end
  end
end

Evenodd.start()