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

Solution Threads

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Keep all content related to advent of code in some way
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console.log('Hello World')

founded 1 year ago

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☃️ - 2023 DAY 4 SOLUTIONS -☃️ (programming.dev)

submitted 11 months ago* (last edited 11 months ago) by Ategon@programming.dev to c/advent_of_code@programming.dev

48 comments fedilink hide all child comments

Day 4: Scratchcards

Megathread guidelines

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/ or pastebin (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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What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
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[–] sjmulder@lemmy.sdf.org 2 points 11 months ago (1 children)

Language: C

Another day of parsing, another day of strsep() to the rescue. Today was one of those satisfying days where the puzzle text is complicated but the solution is simple once well understood.

GitHub link

:::spoiler Code (29 lines)

int main()
{
	char line[128], *rest, *tok;
	int nextra[200]={0}, nums[10], nnums;
	int p1=0,p2=0, id,val,nmatch, i;

	for (id=0; (rest = fgets(line, sizeof(line), stdin)); id++) {
		nnums = nmatch = 0;

		while ((tok = strsep(&amp;rest, " ")) &amp;&amp; !strchr(tok, ':'))
			;
		while ((tok = strsep(&amp;rest, " ")) &amp;&amp; !strchr(tok, '|'))
			if ((val = atoi(tok)))
				nums[nnums++] = val;
		while ((tok = strsep(&amp;rest, " ")))
			if ((val = atoi(tok)))
				for (i=0; i

[–] mykl@lemmy.world 1 points 11 months ago (1 children)

Looks like Lemmy's odd parsing broke your comment at the less-than sign.

[–] sjmulder@lemmy.sdf.org 1 points 11 months ago (1 children)

That's unfortunate, although it looks good on my instance (SDF). Anything I could do?

[–] mykl@lemmy.world 1 points 11 months ago

Ohh that’s interesting, I’ve seen a few comments about mishandling of special chars in code blocks and assumed it was a server issue, maybe it’s fixed in newer releases or perhaps it’s client side.