bunny_hq.rb

# google advent of code solution #1

input = File.read "instructions.txt"

instructions = input.split ', '

# first is left, second is right
directions = {
  :north => [:west,  :east],
  :east  => [:north, :south],
  :south => [:east,  :west],
  :west  => [:south, :north],
}

current_coord = { :x => 0, :y => 0 }

facing_direction = :north

instructions.each do |instruction|
  direction = instruction[0]
  distance  = instruction[1..-1].to_i

  if direction == "L"
    new_facing_direction = directions[facing_direction].first
  else
    new_facing_direction = directions[facing_direction].last
  end

  puts "#{new_facing_direction} for #{distance} blocks"
  facing_direction = new_facing_direction

  if facing_direction == :north
    current_coord[:y] += distance
  elsif facing_direction == :east
    current_coord[:x] += distance
  elsif facing_direction == :south
    current_coord[:y] -= distance
  elsif facing_direction == :west
    current_coord[:x] -= distance
  end
end

puts current_coord

instructions.txt

L4, R2, R4, L5, L3, L1, R4, R5, R1, R3, L3, L2, L2, R5, R1, L1, L2, R2, R2, L5, R5, R5, L2, R1, R2, L2, L4, L1, R5, R2, R1, R1, L2, L3, R2, L5, L186, L5, L3, R3, L5, R4, R2, L5, R1, R4, L1, L3, R3, R1, L1, R4, R2, L1, L4, R5, L1, R50, L4, R3, R78, R4, R2, L4, R3, L4, R4, L1, R5, L4, R1, L2, R3, L2, R5, R5, L4, L1, L2, R185, L5, R2, R1, L3, R4, L5, R2, R4, L3, R4, L2, L5, R1, R2, L2, L1, L2, R2, L2, R1, L5, L3, L4, L3, L4, L2, L5, L5, R2, L3, L4, R4, R4, R5, L4, L2, R4, L5, R3, R1, L1, R3, L2, R2, R1, R5, L4, R5, L3, R2, R3, R1, R4, L4, R1, R3, L5, L1, L3, R2, R1, R4, L4, R3, L3, R3, R2, L3, L3, R4, L2, R4, L3, L4, R5, R1, L1, R5, R3, R1, R3, R4, L1, R4, R3, R1, L5, L5, L4, R4, R3, L2, R1, R5, L3, R4, R5, L4, L5, R2