12c.rb

# part 1
p, h = 0.to_c, 1.to_c
data.lines.each do |s|
  d = s[1..].to_i
  case s[0]
  when 'N' then p += d * 1i
  when 'S' then p += d * -1i
  when 'E' then p += d
  when 'W' then p -= d
  when 'L' then (d / 90).times { h *= 1i }
  when 'R' then (d / 90).times { h *= -1i }
  when 'F' then p += h * d
  end
end
puts p.real.abs + p.imag.abs

# part 2
s, p = 0.to_c, 10 + 1i
data.lines.each do |line|
  d = line[1..].to_i
  case line[0]
  when 'N' then p += d * 1i
  when 'S' then p += -d * 1i
  when 'E' then p += d
  when 'W' then p -= d
  when 'L' then (d / 90).times { p *= 1i }
  when 'R' then (d / 90).times { p *= -1i }
  when 'F' then s += p * d
  end
end
puts s.real.abs + s.imag.abs