2019/11/8 ラウンドテーブルのお題

quiz.ex

defmodule Quiz do
  @moduledoc """
  Documentation for Quiz.
  """

  @doc """
  Search treasure!!!

  ## Examples

      iex> Quiz.search([ [0, 0, 1, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0] ])
      "0,2"

      iex> Quiz.search([ [0, 0, 0, 0], [0, 0, 0, 0], [0, 1, 0, 0], [0, 0, 0, 0] ])
      "2,1"

  """
  def search(lists) do
    first =
      lists
      |> Enum.find_index(fn list ->
        list |> Enum.any?(fn v -> v == 1 end)
      end)

    second =
      lists
      |> Enum.reduce(0, fn list, acc ->
        acc + Quiz.convert(list |> Enum.find_index(fn v -> v == 1 end))
      end)

    "#{first},#{second}"
  end

  def convert(nil), do: 0
  def convert(num), do: num
end