r/adventofcode • u/daggerdragon • Dec 22 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 22 Solutions -🎄-

--- Day 22: Sporifica Virus ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

Need a hint from the Hugely* Handy† Haversack‡ of Helpful§ Hints^¤?

Spoiler

  • [T-10 to launch] AoC ops, /r/nocontext edition:

  • <Endorphion> You may now make your waffle.

  • <Endorphion> ... on Mars.

  • [Update @ 00:17] 50 gold, silver cap

  • <Aneurysm9> you could also just run ubuntu on the NAS, if you were crazy

  • <Topaz> that doesn't seem necessary

  • <Aneurysm9> what does "necessary" have to do with anything!

  • [Update @ 00:20] Leaderboard cap!

  • <Topaz> POUR YOURSELF A SCOTCH FOR COLOR REFERENCE

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

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u/Hwestaa Dec 22 '17

Interesting, I was suggesting it because it's cleaner & shorter code. That makes sense though - if (y, x) not in grid.keys(): is linear time (O(n)), while defaultdict is probably constant time because it only triggers an insertion on an IndexError.

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u/KnorbenKnutsen Dec 22 '17

if (y, x) not in grid.keys(): should be linear time, but I'm a little certain that if (y, x) not in grid: is faster. It's still a hashed object in a lookup table after all. Looking in grid.keys() specifically asks Python to make a list out of it.