Advent Of Code

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An unofficial home for the advent of code community on programming.dev!

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

AoC 2023

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console.log('Hello World')

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🎄 - 2023 DAY 15 SOLUTIONS -🎄 (self.advent_of_code)

submitted 11 months ago* (last edited 11 months ago) by Ategon to c/advent_of_code

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Day 15: Lens Library

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Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
Code block support is not fully rolled out yet but likely will be in the middle of the event. Try to share solutions as both code blocks and using something such as https://topaz.github.io/paste/ , pastebin, or github (code blocks to future proof it for when 0.19 comes out and since code blocks currently function in some apps and some instances as well if they are running a 0.19 beta)

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[–] [email protected] 4 points 11 months ago

C

Yes, it's a hash table. Did I pick a language with built in hash tables? Of course I didn't. Could I have used one of the many libraries implementing one? Sure. But the real question is, can we make do with stuffing things into a few static arrays at nearly zero memory and runtime cost? Yes!

In the spirit of Fred Brooks, it’ll suffice here to show my data structures:

struct slot { char label[8]; int lens; };
struct box { struct slot slots[8]; int nslots; };

static struct box boxes[256];

https://github.com/sjmulder/aoc/blob/master/2023/c/day15.c