Zero-prefix numbers

2020/day5/day5.ex

@@ -1,67 +0,0 @@
-defmodule Day5 do
-  defp read_input do
-    Path.expand('input', Path.dirname(__ENV__.file))
-    |> File.read!()
-  end
-
-  defp half_range({lo, hi}, half) do
-    halfway = lo + div(hi + 1 - lo, 2)
-    lower = {lo, halfway - 1}
-    upper = {halfway, hi}
-
-    case half do
-      :lower -> lower
-      :upper -> upper
-    end
-  end
-
-  defp parse_seat(line) do
-    %{row: {r, r}, col: {c, c}} =
-      String.codepoints(line)
-      |> Enum.reduce(%{row: {0, 127}, col: {0, 7}}, fn char, %{row: row, col: col} ->
-        case char do
-          "F" -> %{row: half_range(row, :lower), col: col}
-          "B" -> %{row: half_range(row, :upper), col: col}
-          "L" -> %{row: row, col: half_range(col, :lower)}
-          "R" -> %{row: row, col: half_range(col, :upper)}
-        end
-      end)
-
-    {r, c}
-  end
-
-  defp seat_id({r, c}) do
-    r * 8 + c
-  end
-
-  def part1 do
-    read_input()
-    |> String.split()
-    |> Enum.map(&parse_seat/1)
-    |> Enum.map(&seat_id/1)
-    |> Enum.max()
-  end
-
-  defp find_hole(seat_ids) do
-    [{lo, hi}] =
-      Enum.zip(
-        Enum.slice(seat_ids, 0..-2),
-        Enum.slice(seat_ids, 1..-1)
-      )
-      |> Enum.filter(fn {a, b} -> b - a != 1 end)
-
-    lo + 1
-  end
-
-  def part2 do
-    read_input()
-    |> String.split()
-    |> Enum.map(&parse_seat/1)
-    |> Enum.map(&seat_id/1)
-    |> Enum.sort()
-    |> find_hole
-  end
-end
-
-Day5.part1() |> IO.inspect()
-Day5.part2() |> IO.inspect()