Advent of Code 2023 - Day 01

Mix.install([
  :kino,
  {:kino_aoc, git: "https://github.com/ljgago/kino_aoc"}
])

Input

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2023", "1", System.fetch_env!("LB_AOC_SESSION"))

Part 1

test_input_part1 = """
1abc2
pqr3stu8vwx
a1b2c3d4e5f
treb7uchet
"""

input_field =
  Kino.Input.select("input", [
    {test_input_part1, "Test Input"},
    {puzzle_input, "Puzzle Input"}
  ])

input_field
|> Kino.Input.read()
|> String.split("\n", trim: true)
|> Enum.map(&String.replace(&1, ~r/[^\d]/, ""))
|> Enum.map(&amp;(String.at(&amp;1, 0) <> String.at(&amp;1, -1)))
|> Enum.map(&amp;String.to_integer/1)
|> Enum.sum()

Part 2

test_input_part2 = """
two1nine
eightwothree
abcone2threexyz
xtwone3four
4nineeightseven2
zoneight234
7pqrstsixteen
"""

input_field =
  Kino.Input.select("input", [
    {test_input_part2, "Test Input"},
    {puzzle_input, "Puzzle Input"}
  ])

defmodule Task2 do
  @digits %{
    "one" => 1,
    "two" => 2,
    "three" => 3,
    "four" => 4,
    "five" => 5,
    "six" => 6,
    "seven" => 7,
    "eight" => 8,
    "nine" => 9
  }

  def solve(input) do
    input
    |> String.split("\n", trim: true)
    |> Enum.map(&convert_line/1)
    |> Enum.sum()
  end

  def convert_line(line) do
    10 * first_digit(line) + last_digit(line)
  end

  for digit <- 1..9 do
    string = Integer.to_string(digit)
    defp first_digit(<>), do: unquote(digit)
    defp last_digit(<>), do: unquote(digit)
  end

  for {string, digit} <- @digits do
    reverse_string = String.reverse(string)
    defp first_digit(<>), do: unquote(digit)
    defp last_digit(<>), do: unquote(digit)
  end

  defp first_digit(<<_::utf8, rest::binary>>), do: first_digit(rest)
  defp last_digit(<<_::utf8, rest::binary>>), do: last_digit(rest)
end

input_field
|> Kino.Input.read()
|> Task2.solve()