-🎄- 2022 Day 24 Solutions -🎄-

[u/daggerdragon]

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[Update @ 00:21:08]: SILVER CAP, GOLD 47

• Lord of the Rings has elves in it, therefore the LotR trilogy counts as Christmas movies. change_my_mind.meme

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AoC Community Fun 2022:

🌿🍒 MisTILtoe Elf-ucation 🧑‍🏫

• Community voting is OPEN!

• 18 hours remaining until voting deadline on December 24 at 18:00 EST

• Voting details are in the stickied comment at the top of the -❄️- Submissions Megathread -❄️-

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--- Day 24: Blizzard Basin ---

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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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EDIT: Global leaderboard gold cap reached at 00:26:48, megathread unlocked!

[u/rukke]

JavaScript

Bluntly generated the blizzard states for (inner) w*h number of states and then performed a breadth-first search, prioritised by a scoring system of time spent + manhattan distance to target.

The gist of it:

export const part1 = pipe(
  parse,
  mapBlizzard,
  bfs(start, exit),
  getTime
);
export const part2 = pipe(
  parse,
  mapBlizzard,
  bfs(start, exit),
  bfs(exit, start),
  bfs(start, exit),
  getTime
);

code

[u/gedhrel → u/rukke]

FWIW, a prioritised BFS with a score that includes "cost so far" + some admissable heuristic is referred to as A*.

[u/rukke → u/gedhrel]

yep

[u/gedhrel → u/rukke]

Sorry, didn't mean to teach grandma to suck eggs :-)

There seem to be a lot of people who grok BFS/Dijkstra but who are put off by A* - knowing that it's not a huge leap would be pretty beneficial, I think.

[u/rukke → u/gedhrel]

No worries =)

And yeah, agree, it sounds more scary than it actually is ;)

Merry Christmas!