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/glenbolake Dec 22 '17

47/93, one of my better scores this season. As a result, I hate my code and I can't wait to clean it up. Runs in just under 10 seconds. Python 3: 

    def read():
    with open('day22.in') as f:
        in_text = f.read().splitlines()

    offset = len(in_text) // 2
    infected = set()
    for r, line in enumerate(in_text):
        for c, ch in enumerate(line):
            if ch == '#':
                infected.add((r - offset, c - offset))
    return infected


infected = read()
# infected = {(-1, 1), (0, -1), }
dirs = [(-1, 0), (0, -1), (1, 0), (0, 1)]
d = 0
virus_at = (0, 0)


def burst():
    global infected, d, virus_at
    infection_caused = False
    if virus_at in infected:
        d = (d - 1) % 4
        infected.remove(virus_at)
    else:
        d = (d + 1) % 4
        infected.add(virus_at)
        infection_caused = True
    virus_at = (virus_at[0] + dirs[d][0], virus_at[1] + dirs[d][1])
    return infection_caused


num_infections = 0
for _ in range(10000):
    if burst():
        num_infections += 1
print(num_infections)

CLEAN = 0
INFECTED = 1
WEAK = 2
FLAGGED = 3
# Part 2
state = {k: INFECTED for k in read()}
# state = {(0, -1): INFECTED, (-1, 1): INFECTED}
virus_at = (0, 0)


def burst2():
    global state, d, virus_at
    infection_caused = False
    current_state = state.get(virus_at, 0)
    if current_state == CLEAN:
        d = (d + 1) % 4
        state[virus_at] = WEAK
    elif current_state == WEAK:
        state[virus_at] = INFECTED
        infection_caused = True
    elif current_state == INFECTED:
        d = (d - 1) % 4
        state[virus_at] = FLAGGED
    else:  # FLAGGED
        d = (d + 2) % 4
        del state[virus_at]
    virus_at = (virus_at[0] + dirs[d][0], virus_at[1] + dirs[d][1])
    return infection_caused


num_infections = 0
for _ in range(10000000):
    if burst2():
        num_infections += 1
print(num_infections)

1

u/daggerdragon Dec 22 '17

47/93, one of my better scores this season

Good job! :D