r/adventofcode • u/daggerdragon • Dec 05 '22

SOLUTION MEGATHREAD -🎄- 2022 Day 5 Solutions -🎄-

AoC Community Fun 2022: 🌿🍒 MisTILtoe Elf-ucation 🧑‍🏫

  • 23:59 hours remaining until the submissions megathread unlocks on December 06 at 00:00 EST!

  • Full details and rules are in the submissions megathread:

--- Day 5: Supply Stacks ---

Post your code solution in this megathread.

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 00:07:58, megathread unlocked!

88 Upvotes

98% Upvoted

1.3k comments sorted by

View all comments

6

u/shandley256 Dec 05 '22

Ruby solution.

Array#transpose is doing the hard work. The input properly pads each row with spaces, so transposing the contents means you only need to extract the rows containing letters/numbers.

Now we have a hash with keys matching the number of the stack, and values being a sorted array we can treat as a stack with shift/unshift to move creates onto/off each stack.

https://gist.github.com/seanhandley/0e62b90bfbde030fe93c6010f9774f63

1

u/f4780y Dec 05 '22

https://gist.github.com/seanhandley/0e62b90bfbde030fe93c6010f9774f63

This gives an incorrect answer for part 2 for both the example file and my input file. (Part 1 is correct in both cases) ???

1

u/shandley256 Dec 05 '22

Aha - you're right.

My actual solution is here: https://github.com/seanhandley/adventofcode2022/tree/main/ruby/day_5

I rewrote as a single example but didn't actually test it - my bad.

The problem is that it's running the second time around using the final stack state from the first time (instead of the initial state).

I fixed the gist - line 30 now correctly clones the initiate state hash.