class Room
  attr_reader :name, :sector_id, :checksum

  def initialize(string)
    @name = string.split("-")[..-2].join("-")
    @sector_id = string.split("-")[-1].split("[")[0].to_i
    @checksum = string.split("[")[1][..-2]
  end

  def calculated_checksum
    letter_counts.sort_by { |k, v| [-v, -k] }.map(&:first)[0...5].join
  end

  def real?
    calculated_checksum == checksum
  end

  def letter_counts
    (name.chars - ["-"]).group_by(&:itself).to_h { |k, v| [k, v.count] }
  end

  def rotated_name
    1.upto(sector_id % 26).reduce(name) { |n, _| n.codepoints.map{ |c| ((((c + 1) - 97) % 26) + 97).chr }.join("") }
  end
end

input = STDIN.read.chomp
room_lines = input.split("\n")
rooms = room_lines.map { |line| Room.new line }
part_1 = rooms.select(&:real?).sum(&:sector_id)

puts "Part 1: #{part_1}"

part_2 = rooms.find { |room| room.rotated_name.include? "northpole" }.sector_id

puts "Part 2: #{part_2}"