Advent Of Code

768 readers

1 users here now

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

M	T	W	T	F	S	S
				1	2	3
4	5	6	7	8	9	10
11	12	13	14	15	16	17
18	19	20	21	22	23	24
25

Rules/Guidelines

Follow the programming.dev instance rules
Keep all content related to advent of code in some way
If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2023 Day 10])
When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts

Relevant Communities

Relevant Links

Advent of Code Homepage

Credits

Icon base by Lorc under CC BY 3.0 with modifications to add a gradient

console.log('Hello World')

founded 1 year ago

MODERATORS

[email protected]

🎁 - 2023 DAY 5 SOLUTIONS -🎁 (programming.dev)

submitted 11 months ago* (last edited 11 months ago) by [email protected] to c/[email protected]

39 comments fedilink hide all child comments

Day 5: If You Give a Seed a Fertilizer

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/ , 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)

FAQ

What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
Where do I participate?: https://adventofcode.com/
Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465

🔒This post will be unlocked when there is a decent amount of submissions on the leaderboard to avoid cheating for top spots

🔓 Unlocked after 27 mins (current record for time, hard one today)

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 5 points 11 months ago (1 children)

I got far enough to realize that you probably needed to work backwards and given a location, determine the accompanying seed, and then check if that seed is one of the ones listed in the range. Still though, starting at 0 for location and working up was taking forever to find the first valid seed

Someone in this thread pointed out that if you picked the first value of each range in the map, working backwards from those points will get you a short list of seeds which map to low values. You then check if those seeds are valid, and also check the location of the first seeds in the range (the rest of the seeds in the range don't matter because those are covered by the first check). This ends up with about 200 locations which you can sort, to get the lowest value.

[–] [email protected] 3 points 11 months ago

I tried brute forcing it but couldn't get the process to finish. Iterating through hundreds of millions of seeds is no bueno.

After reading your comment though I got the idea to map whole seed ranges instead of individual seeds. That finished in no time of course.