aoc2021_day4.exs

defmodule Board do
  defstruct numbers: %{}, hits: %{}, last_match: nil

  def parse_xy_val(lines) when is_list(lines) do
    board =
      lines
      |> Enum.with_index()
      |> Enum.reduce(%{}, &parse_line_xy_val/2)

    %__MODULE__{numbers: board}
  end

  def parse_val_xy(lines) when is_list(lines) do
    board =
      lines
      |> Enum.with_index()
      |> Enum.reduce(%{}, &parse_line_val_xy/2)

    %__MODULE__{numbers: board}
  end

  defp parse_line_xy_val({line, row_num}, board) do
    line
    |> String.split()
    |> Enum.map(&String.to_integer/1)
    |> Enum.with_index()
    |> Enum.reduce(board, fn {val, col}, acc ->
      Map.put(acc, {row_num, col}, val)
    end)
  end

  defp parse_line_val_xy({line, row_num}, board) do
    line
    |> String.split()
    |> Enum.map(&String.to_integer/1)
    |> Enum.with_index()
    |> Enum.reduce(board, fn {val, col}, acc ->
      Map.put(acc, val, {row_num, col})
    end)
  end
end

"""
22 13 17 11  0
 8  2 23  4 24
21  9 14 16  7
 6 10  3 18  5
 1 12 20 15 19
"""
|> String.split("\n")
|> Enum.map(&String.trim/1)
|> Board.parse_xy_val()
|> IO.inspect(label: "Board {x, y} -> val")

"""
22 13 17 11  0
 8  2 23  4 24
21  9 14 16  7
 6 10  3 18  5
 1 12 20 15 19
"""
|> String.split("\n")
|> Enum.map(&String.trim/1)
|> Board.parse_val_xy()
|> IO.inspect(label: "Board val -> {x, y}")