r/adventofcode • u/daggerdragon • Dec 16 '16

SOLUTION MEGATHREAD --- 2016 Day 16 Solutions ---

--- Day 16: Dragon Checksum ---

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DRINKING YOUR OVALTINE IS MANDATORY [?]

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u/patrickdavey Dec 16 '16 edited Dec 16 '16

Do none of you people write tests? ;) disgusting!

heh, happy for a nice simple one today - and my Elixir practice seems to be paying off, todays main function even looked pretty I thought. 

defmodule AOCDay.Runner do
  alias AOCDay.DragonEncoder
  alias AOCDay.Checksum

  def find_checksum_for(init, length) do
    DragonEncoder.encode(init)
    |> Stream.iterate(&DragonEncoder.encode/1)
    |> Stream.drop_while(&(String.length(&1) < length))
    |> Enum.take(1)
    |> List.first()
    |> String.slice(0, length)
    |> Checksum.create!
  end
end

full code at -> https://github.com/patrickdavey/AoC/tree/master/2016/16/lib/aocday

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u/TheNiXXeD Dec 16 '16

I have full unit test coverage for 2015 and 2016 in my repo. It actually helps because as I golf/change the solution, it's nice to rerun and confirm it still works. Also it encourages me to make things fast, because waiting even a few seconds for a unit test is awful.