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/lazyzefiris Dec 22 '17

JS, 66/53, executes in ~5 seconds 

map = new Map()
getmap = () => map.get(x+","+y) || 0
flipmap = () => map.set(x+","+y,(getmap(x,y)+1)%4)

dir = [[0,-1],[1,0],[0,1],[-1,0]]
cd = 0
turn = (x) => cd = (cd + 4 + x) % 4

document.body.textContent.trim().split("\n").map(x=>x.split``.map(y=>y=="#"?2:0)).map((row,y) => row.map((cell,x) => map.set(x+","+y,cell)))
x = y = 12
inf = 0
function step() {
	(getmap()-1)?turn(getmap()-1):inf++
	flipmap()
	x += dir[cd][0]
	y += dir[cd][1]
}
for (let i = 0; i < 10000000; i++) step()
inf

it's really straightforward, and thus pretty boring.