Advent of Code 2024, Day 3

recovery.rb

require "minitest/autorun"

class Recovery
  def initialize(input, parser: BasicParser)
    @input = input
    @parser = parser
  end

  def total
    data.sum { |x, y| x.to_i * y.to_i }
  end

  private

    def data
      @data ||= @parser.new(@input).parse
    end
end

class BasicParser
  PATTERN = /mul\((\d{1,3}),(\d{1,3})\)/

  def initialize(input)
    @input = input
  end

  def parse
    @input.scan(PATTERN)
  end
end

class ConditionalParser
  PATTERN = /mul\((\d{1,3}),(\d{1,3})\)|(do\(\))|(don't\(\))/

  def initialize(input)
    @input = input
    @active = true
  end

  def parse
    commands.each_with_object([]) do |command, instructions|
      case command.first
      when "do()"
        @active = true
      when "don't()"
        @active = false
      else
        instructions << command if @active
      end
    end
  end

  private

    def commands
      @input.scan(PATTERN).map(&:compact)
    end
end

BLUE = "\e[34m"
YELLOW = "\e[33m"
RESET = "\e[0m"

recovery = Recovery.new(File.read(ARGV[0]))
puts "#{BLUE}Transaction Total: #{YELLOW}#{recovery.total}#{RESET}"
conditional_recovery = Recovery.new(File.read(ARGV[0]), parser: ConditionalParser)
puts "#{BLUE}Conditional Transaction Total: #{YELLOW}#{conditional_recovery.total}#{RESET}"


PART_1_INPUT = "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))"
PART_2_INPUT = "xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))"

class RecoveryTest < Minitest::Test
  def test_part_1_total
    recover_memory = Recovery.new(PART_1_INPUT)
    assert_equal 161, recover_memory.total
  end

  def test_part_2_total
    recover_memory = Recovery.new(PART_2_INPUT,  parser: ConditionalParser)
    assert_equal 48, recover_memory.total
  end
end

class BasicParserTest < Minitest::Test
  def test_parse
    basic_parser = BasicParser.new PART_1_INPUT
    expected = [["2","4"], ["5","5"], ["11","8"], ["8","5"]]
    assert_equal expected, basic_parser.parse
  end
end

class ConditionalParserTest < Minitest::Test
  def test_parse
    conditional_parser = ConditionalParser.new PART_2_INPUT
    assert_equal [["2", "4"], ["8","5"]], conditional_parser.parse
  end
end