Advent of Code 2024, Day 1: ruby location_data.rb day_1.txt

location_data.rb

require "minitest/autorun"

INPUT = DATA.read

class LocationDataTest < Minitest::Test
  def test_total_distance
    location_list = LocationData.new(INPUT)
    assert_equal 11, location_list.total_distance
  end

  def test_similarity_score
    location_list = LocationData.new(INPUT)
    assert_equal 31, location_list.similarity_score
  end

  def test_distance
    location_list = LocationData.new(INPUT)
    assert_equal 2, location_list.distance(1, 3)
    assert_equal 1, location_list.distance(2, 3)
    assert_equal 0, location_list.distance(3, 3)
    assert_equal 1, location_list.distance(3, 4)
    assert_equal 2, location_list.distance(3, 5)
    assert_equal 5, location_list.distance(4, 9)
  end

  def test_similarity
    location_list = LocationData.new(INPUT)
    assert_equal 9, location_list.similarity(3)
    assert_equal 4, location_list.similarity(4)
    assert_equal 0, location_list.similarity(2)
    assert_equal 0, location_list.similarity(1)
  end

  def test_ordered_data
    location_list = LocationData.new(INPUT)
    ordered = [[1, 3], [2, 3], [3, 3], [3, 4], [3,5], [4, 9]]
    assert_equal ordered, location_list.ordered_data
  end

  def test_left_list
    location_list = LocationData.new(INPUT)
    assert_equal [3, 4, 2, 1, 3, 3], location_list.left_list
  end

  def test_right_list
    location_list = LocationData.new(INPUT)
    assert_equal [4, 3, 5, 3, 9, 3], location_list.right_list
  end
end

class LocationData
  attr_reader :data

  def initialize(input)
    @data = parse input
  end

  def total_distance
    ordered_data.reduce(0) { |total, pair| total + distance(*pair) }
  end

  def similarity_score
    left_list.reduce(0) { |total, location| total + similarity(location) }
  end

  def distance(left, right)
    (left - right).abs
  end

  def similarity(location)
    location * (right_list.tally[location] || 0)
  end

  def ordered_data
    data.transpose.map(&:sort).transpose
  end

  def left_list
    data.transpose[0]
  end

  def right_list
    data.transpose[1]
  end

  private
    
    def parse(input)
      input.split("\n").map { |x| x.split.map(&:to_i) }
    end
end

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

location_list = LocationData.new(File.read(ARGV[0]))
puts "#{BLUE}Total Distance:#{RESET} #{YELLOW}#{location_list.total_distance}#{RESET}"
puts "#{BLUE}Similarity Socre:#{RESET} #{YELLOW}#{location_list.similarity_score}#{RESET}"

__END__
3   4
4   3
2   5
1   3
3   9
3   3