Advent Of Code 2016 Day 01

aoc_2016_day1_part1.rb

path = [[]]
file = File.open("input.txt")
contents = file.read
split = contents.split(", ")
split.each do |s|
  m = s.match(/([L|R])(\d+)/)
  l = m[1]
  n = m[2]
  path << [l, n.to_i]
end
x = 0
y = 0
d = 0
path.each do |p|
  case p[0]
  when 'L'
    d = (d - 1) % 4
  when 'R'
    d = (d + 1) % 4
  end
  next if p.empty?
  case d
  when 0
    y += p[1]
  when 1
    x += p[1]
  when 2
    y -= p[1]
  when 3
    x -= p[1]
  end
end

p x.abs + y.abs

aoc_2016_day1_part2.rb

path = [[]]
file = File.open("input.txt")
contents = file.read
split = contents.split(", ")
split.each do |s|
  m = s.match(/([L|R])(\d+)/)
  l = m[1]
  n = m[2]
  path << [l, n.to_i]
end
x = 0
y = 0
d = 0
pos = {}
path.each do |p|
  case p[0]
  when 'L'
    d = (d - 1) % 4
  when 'R'
    d = (d + 1) % 4
  end
  next if p.empty?

  p[1].times do |i|
    case d
    when 0
      y += 1
    when 1
      x += 1
    when 2
      y -= 1
    when 3
      x -= 1
    end
    if pos[[x,y]] != nil
      pos[[x, y]] += 1
    else
      pos[[x,y]] = 1
    end
    if pos[[x,y]] == 2
      res = x+y
      puts res.abs
      puts pos[[x,y]]
      exit 0
    end
  end
end