Day 08

Mix.install([
  {:kino, "~> 0.14.2"}
])

IEx.Helpers.c("/Users/johnb/dev/2015adventOfCode/advent_of_code.ex")
alias AdventOfCode, as: AOC
alias Kino.Input
require Integer
use Bitwise

# Note: when making the next template, something like this works well:
#   `cat day01.livemd | sed 's/01/02/' > day02.livemd`
#

Installation and Data

input_p1example = Kino.Input.textarea("Example Data")

input_p1puzzleInput = Kino.Input.textarea("Puzzle Input")

input_source_select =
  Kino.Input.select("Source", [{:example, "example"}, {:puzzle_input, "puzzle input"}])

p1data = fn ->
  (Kino.Input.read(input_source_select) == :example &&
     Kino.Input.read(input_p1example)) ||
    Kino.Input.read(input_p1puzzleInput)
end

Part 1

defmodule Day08 do
  def solve1(text) do
    lines = AOC.as_single_lines(text)
    
    lines
    |> Enum.map(fn line ->
      center = String.slice(line, 1..-2//1)
      outer_quote_length = 2
      inner_quotes_and_slashes = Regex.scan(~r/(\\"|\\\\)/, center)
      escaped_chars = Regex.scan(~r/(\\x[0-9a-f][0-9a-f])/, center)

      # Just count the extra chars needed 
      (outer_quote_length +
        Enum.count(inner_quotes_and_slashes) +
        Enum.count(escaped_chars) * 3)
    end)
    |> Enum.sum()
  end

  def solve2(text) do
    lines = AOC.as_single_lines(text)
    
    lines
    |> Enum.map(fn line ->
      center = String.slice(line, 1..-2//1)
      outer_quote_length = 2
      inner_quotes_and_slashes = Regex.scan(~r/("|\\)/, center)

      # Just count the extra chars needed 
      (outer_quote_length * 2 +
        Enum.count(inner_quotes_and_slashes) 
      )
    end)
    |> Enum.sum()
  end
end

# Example data:
# ""
# "abc"
# "aaa\"aaa"
# "\x27"

p1data.()
|> Day08.solve1()
|> IO.inspect(label: "\n*** Part 1 solution (example: 12)")
# 1362 is too high
# 1350 is correct after ensuring hex chars

p1data.()
|> Day08.solve2()
|> IO.inspect(label: "\n*** Part 2 solution (example: 19)")
# 2085