Advent of Code 2024 Day 14 (Base A Style)

[MeganBowers]

Discussion thread for day 14 of the Advent of Code - https://adventofcode.com/2024/day/14

[cgoodman3]

Spoiler

Part 1 I was able to approach it using mod() to deal with the wrapping and not need to generate every step to 100.
I used Excel to check that this was the right logic:

As @CoG mentions mod() in Alteryx can provide negative numbers, whereas Excel doesn't.  To deal with negatives I used an if statement

if [newgrid_px] < 0 THEN 
[User.maxx] + [newgrid_px]
Else [newgrid_px]
ENDIf​

Part 2 is similar to day 10 in 2018, where there is a point where the stars align, or in today's case the robots.
After running a few 1,000 iterations I could see there were certain rows and columns which had a lot of robots in a line, so filtered to these. Then it was a case of increasing the iterations to cover the periodicy of the problem, which created a very clear outcome where the number of robots in line (I essentially was finding the frame around the Christmas tree) was the maximum.
 
Which gave me a nice solve without needing to hunt through 1,000s of images - so my workflow at the end creates a nice Christmas tree.

[DataNath]

Day 14 in the bag! Used @ScottLewis' tip for part 2 - looking for a line of 6 points returned a single output which was my Christmas tree! Not very neat so maybe my flow is off slightly but we picked up 2 stars!

Spoiler

[Hub119]

Part 1 was pretty straightforward... Part 2 wasn't too bad once I figured out which logic to apply to it... and determined that it wasn't going to be ALL the robots that would align so shifted which metric I was tracking. 14 down, 11 to go!

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Workflow

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Tree Image

[mmontgomery]

Day14. More in spoiler

Spoiler

P1: Did a simple macro to account for each position since was 100 iterations
P2: Brute force 10k combos and write down two distinct patterns appearing horizontally and vertically, then figure out the delta between them and create possible combos with generate rows to narrow the search. I saw it visually in the report map

[DaisukeTsuchiya]

I update WF for P2 without checking thousands loops.

Spoiler

The task involved reassembling scattered robots, so I calculated the standard deviation of the XY coordinates for each loop and examined the smallest one. As expected, the case with the smallest standard deviation turned out to be the solution.

Spoiler

[Tokimatsu]

At first I could not imagine the goal picture.

Spoiler

I tried to check for line symmetry placement, but failed. Next, they looked at 300 pictures in each sequence. Then we found a repeating pattern.Then found P2 answer. After that create the workflow to find the goal.

 

[Carolyn]

Solved. I'm not sure how I feel about Part 2. I wouldn't have gotten there without the help from everyone. I definitely would've preferred more guidance on what "make a Xmas tree" actually looked like, since I assumed it was set in the middle of the graph

Spoiler

For Part 2, I did a Generate Rows for 101 * 103 Rows. Then I did a Group By Iteration and End_X and Group By Iteration and End_Y. I filtered each for where the Count was > 15 (it seemed like a good number), joined them together, and found the first iteration on both. 

[kelsey_kincaid]

This was challenging but fun! 

Spoiler

I spun my wheels for way too long on Part 1. I fixed the issue by simply adding 1 to all of my starting coordinates. Having zeroes was making the math confusing, and I wish I'd just adjusted the coordinates sooner. I managed the "teleports" by finding a multiplier that adjusted the coordinates.

Formula Examples:


For Part 2, I iterated 10,000 times and then found the iteration with the smallest standard deviation between points. I got a lot of inspiration for this solution and visualization from some previous year solutions from @phottovy and @cgoodman3 that they highlighted recently. Without that, I would have spun my wheels trying to figure this one out. Just goes to show how much of a learning opportunity Advent of Code is!

There's probably a way to get the macro to exit early instead of hardcoding the iterations, but this only ran in 25.6 seconds so I'm OK with it the way it is :) 

[Qiu]

@Tokimatsu 
Very brilliant idea.
I did same approach but went to calculate the area of Christmas Tree.

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[Shifty]

Just part 1 for me.  Part 2 seems mad.

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