소개

$ mix new list_of_lists
$ cd list_of_lists

1. 소스 코드 작성

예, 동

defmodule ListOfLists do
  @n 3
  @m 3
  @timeout 1000

  def main do
    [head | tail] = results()

    print({head, {nil, nil}})
    Process.sleep(@timeout)

    Enum.zip(tail, for(i <- 0..(@n - 1), j <- 0..(@m - 1), do: {i, j}))
    |> Enum.zip(List.duplicate(@timeout, @n * @m))
    |> Enum.flat_map(fn {a, b} -> [a, b] end)
    |> Enum.each(&print/1)

    Enum.at(tail, -1) |> to_s(@n - 1, @m - 1, false) |> IO.puts()
  end

  defp results do
    for(i <- 0..(@n - 1), j <- 0..(@m - 1), do: {i, j})
    |> Enum.reduce([init_list_of_lists(@n, @m)], fn {i, j}, acc ->
      last =
        Enum.at(acc, -1)
        |> get_and_update_in([Access.at(i), Access.at(j)], &{&1, pow(3, i + j)})
        |> elem(1)

      acc ++ [last]
    end)
  end

  defp init_list_of_lists(n, m) do
    1..n |> Enum.map(fn _ -> List.duplicate(0, m) end)
  end

  defp print(n) when is_integer(n), do: Process.sleep(n)

  defp print({list_of_lists, {i, j}}) do
    to_s(list_of_lists, i, j)
    |> IO.puts()
  end

  defp to_s(list_of_lists, i, j, move \\ true, count \\ 5) do
    for(k <- 0..(@n - 1), l <- 0..(@m - 1), do: {k, l})
    |> Enum.map(fn {k, l} ->
      value_with_leading =
        get_in(list_of_lists, [Access.at(k), Access.at(l)])
        |> Integer.to_string()
        |> String.pad_leading(count)

      if k == i && l == j do
        "\x1b[31m#{value_with_leading}\x1b[0m"
      else
        value_with_leading
      end
    end)
    |> Enum.chunk_every(@m)
    |> Enum.map(&Enum.join/1)
    |> Enum.join("\n")
    |> (fn s -> "(#{i}, #{j})\n" <> s end).()
    |> (fn s -> if(move, do: s <> "\x1b[#{@n + 1}A", else: s) end).()
  end

  defp pow(_, 0), do: 1

  defp pow(n, m), do: n * pow(n, m - 1)
end

2. 실행

$ iex -S mix

iex> ListOfLists.main

Wrapping Up

Enjoy Escape characters !!!