class Reindeer attr_reader *%i[ speed time rest ] def initialize(speed, time, rest) @speed, @time, @rest = [speed, time, rest].map(&:to_i) end def distance(current_time) distance = speed * time total_time = time + rest reps = current_time / total_time reps * distance + [current_time % total_time, time].min * speed end end regex = /(\w+) can fly (\d+) km\/s for (\d+) seconds, but then must rest for (\d+) seconds/ reindeer = DATA.read.scan(regex).each.with_object({}) {|(name, speed, time, rest), reindeer| reindeer[name] = Reindeer.new(speed, time, rest) } scores = (1..2503).each.with_object(Hash.new(0)) do |current_time, scores| sorted = reindeer.group_by {|_,r| r.distance(current_time) }.sort sorted.last.last.map(&:first).each do |name| scores[name] += 1 end end puts scores.sort_by(&:last) __END__ Dancer can fly 27 km/s for 5 seconds, but then must rest for 132 seconds. Cupid can fly 22 km/s for 2 seconds, but then must rest for 41 seconds. Rudolph can fly 11 km/s for 5 seconds, but then must rest for 48 seconds. Donner can fly 28 km/s for 5 seconds, but then must rest for 134 seconds. Dasher can fly 4 km/s for 16 seconds, but then must rest for 55 seconds. Blitzen can fly 14 km/s for 3 seconds, but then must rest for 38 seconds. Prancer can fly 3 km/s for 21 seconds, but then must rest for 40 seconds. Comet can fly 18 km/s for 6 seconds, but then must rest for 103 seconds. Vixen can fly 18 km/s for 5 seconds, but then must rest for 84 seconds.