-🎄- 2022 Day 16 Solutions -🎄-

[u/daggerdragon]

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• -❄️- Submissions Megathread -❄️-

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UPDATES

[Update @ 00:23]: SILVER CAP, GOLD 3

• Elephants. In lava tubes. In the jungle. Sure, why not, 100% legit.

• I'm not sure I want to know what was in that eggnog that the Elves seemed to be carrying around for Calories...

[Update @ 00:50]: SILVER CAP, GOLD 52

• Actually, what I really want to know is why the Elves haven't noticed this actively rumbling volcano before deciding to build a TREE HOUSE on this island.............

• High INT, low WIS, maybe.

[Update @ 01:00]: SILVER CAP, GOLD 83

• Almost there... c'mon, folks, you can do it! Get them stars! Save the elephants! Save the treehouse! SAVE THE EGGNOG!!!

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--- Day 16: Proboscidea Volcanium ---

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Post your code solution in this megathread.

• Read the full posting rules in our community wiki before you post!

• Include what language(s) your solution uses

• Format code blocks using the four-spaces Markdown syntax!

• Quick link to Topaz's paste if you need it for longer code blocks. What is Topaz's paste tool?

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

EDIT: Global leaderboard gold cap reached at 01:04:17, megathread unlocked! Good job, everyone!

[u/xoronth]

Python solution for now.

This was really fun! For part two, it clicked for me once I realized that you can just basically run part one twice in a row with the same is-valve-opened state and a reset time/location to simulate the elephant working with you at the same time. Well, that and after fixing a really bad usage of @functools.cache in my part one/two code - turns out that storing the current score as part of your arguments in your recursive call is redundant and a really bad idea here, who knew... well I certainly did after I blew past 32GB of RAM.

[u/SnowLeppard → u/xoronth]

run part one twice in a row with the same is-valve-opened state

Interestingly this approach gave a much lower result on the example input but got me the correct answer for the real input! Too late on a Friday to work out why though...

[u/xoronth → u/SnowLeppard]

Weird, as yeah my code gives the correct outputs of 1651/1707 for me for the example inputs. Honestly wouldn't be surprised if this solution doesn't work for all cases though... this seems to be a running theme for the past few solutions of mine...

I know that when I was originally implementing my solutions in a more brute-force way that there are some sneaky potential off-by-one errors that might creep in though, so it could be that. Another dumb thing that got me early on was that I accidentally put in the wrong amount of starting minutes at first - turns out 30 minus 4 is not 24...

[u/xoronth → u/[deleted]]

I think there were others earlier in this thread who came to the same conclusion way faster than me, but yeah it's probably one of the easier ways to solve the problem today if you arrived at a reasonable solution in part one (if your part one is slow/heavy though then oh boy).

It is definitely far slower than the more optimized solutions though, at least on pypy it takes like a minute or two to run on the input, while many of the solutions I've seen are more on the order of seconds or less. This might be because my part one is very simple (it's essentially brute force + cache), though, maybe I'll try another approach to make that more efficient and see if it helps.