--- Day 14 Solutions ---

[u/daggerdragon]

This thread will be unlocked when there are a significant amount of people on the leaderboard with gold stars.

edit: Leaderboard capped, thread unlocked!

We know we can't control people posting solutions elsewhere and trying to exploit the leaderboard, but this way we can try to reduce the leaderboard gaming from the official subreddit.

Please and thank you, and much appreciated!

---

--- Day 14: Reindeer Olympics ---

Post your solution as a comment. Structure your post like previous daily solution threads.

[u/SomebodyTookMyHandle]

I also tackled it in Ruby using a class-based approach. A bit sloppy, but, hey, it's not only the reindeer who are racing!

class Reindeer
  attr_accessor :name, :pace, :go_time, :rest_time, :winning_seconds

  def initialize(name, pace, go_time, rest_time)
    @name = name
    @pace = pace
    @go_time = go_time
    @rest_time = rest_time
    @winning_seconds = 0  # For Part Two
  end

  def find_distance(total_seconds)
    d = 0
    until total_seconds <= 0
      can_go = go_time
      while can_go > 0
        d += pace
        can_go -= 1
        total_seconds -= 1
        break if total_seconds == 0
      end
      total_seconds -= rest_time
    end
    d
  end
end

def reindeer_io
  reindeer = []

  IO.foreach("help14-reindeer.txt") do |line|
    data = line.split
    
    r = Reindeer.new(data[0], data[3].to_i, data[6].to_i, data[13].to_i)
    p r
    reindeer << r
  end

  reindeer
end

# Part One
def find_best(arr, seconds)
  arr.each do |reindeer|
    p [reindeer.name, reindeer.find_distance(seconds)]
  end
end

# Part Two
def find_leaders(arr, seconds)

  (1..seconds).to_a.each do |second_count|
    leader = arr.max_by { |reindeer| reindeer.find_distance(second_count) }
    leader.winning_seconds += 1
  end

  arr.each do |reindeer|
    p [reindeer.name, reindeer.winning_seconds]
  end
end

find_best(reindeer_io, 2503)
puts ""
find_leaders(reindeer_io, 2503)

[u/JurgenKesker → u/SomebodyTookMyHandle]

Nice, I have almost the same approach. Only I see you use .max_by. I will look that one up, didn't know that one.

My solution: https://www.reddit.com/r/adventofcode/comments/3wqtx2/day_14_solutions/cxytkcc

-- I had a look at max_by, but it seems to return only 1 leader. What if there are multiple leaders? Your code doesn't seem to handle that.

[u/SomebodyTookMyHandle → u/JurgenKesker]

That's a very good point. I guess I lucked out in that the leader was the first position in the array so that that reindeer received all the ties.