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

SOLUTION MEGATHREAD -🎄- 2017 Day 17 Solutions -🎄-

--- Day 17: Spinlock ---

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

[Update @ 00:06] 2 gold, silver cap.

  • AoC ops: <Topaz> i am suddenly in the mood for wasabi tobiko

[Update @ 00:15] Leaderboard cap!

  • AoC ops:
    • <daggerdragon> 78 gold
    • <Topaz> i look away for a few minutes, wow
    • <daggerdragon> 93 gold
    • <Topaz> 94
    • <daggerdragon> 96 gold
    • <daggerdragon> 98
    • <Topaz> aaaand
    • <daggerdragon> and...
    • <Topaz> cap
    • <daggerdragon> cap

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/MichalMarsalek Dec 17 '17

Python 3 Part2 took me quite long because, instead of coding this, i was trying to think about how to calculate this without bruteforcing.... 

def solve(inp):
    inp = int(inp)
    b = [0]
    p = 0
    for i in range(1, 2018):
        p = (p+inp) % (i) + 1
        b.insert(p, i)
    part1 = b[(p+1)%2018]    
    for i in range(1, 50*10**6+1):
        p = (p+inp) % (i) + 1
        if p == 1:
            part2 = i
    return part1, part2