topic Advent of Code 2020 - BaseA Style (Day 10) in General Discussions

Advent of Code 2020 - BaseA Style (Day 10)

Jean-Balteryx — Wed, 09 Dec 2020 22:22:57 GMT

Discussion thread for day 10 of the Advent of Code : https://adventofcode.com/2020/day/10

Re: Advent of Code 2020 - BaseA Style (Day 10)

peter_gb — Thu, 10 Dec 2020 08:17:16 GMT

Well that made my head hurt, drew a few diagrams on paper and tried a few bits out in alteryx but no dice for part 2. Keen to see how it was possible!

Re: Advent of Code 2020 - BaseA Style (Day 10)

jdunkerley79 — Thu, 10 Dec 2020 08:43:12 GMT

Don't think you can brute force part 2... so a little thinking beforehand.

If you want the inner trick for part 2:

A block with steps 113 can have the first 1 removed => so 2 possibilities
A block with steps 1113 can have the first 1, second 1 or both removed => so 4 possibilities
A block with steps 11113 can have first, second, third, first & second, first & third or second & third removed => so 7 possibilities

My data set had no 111113 but think would be 13 possibilities

You can then product these possibilities together to get the total number of possibilities

Re: Advent of Code 2020 - BaseA Style (Day 10)

peter_gb — Thu, 10 Dec 2020 08:58:13 GMT

Genius! I got stuck somewhere in the middle of identifying optional steps, and calculating how many valid next steps each individual step had, but got lost as to how to bring all of that together.

Re: Advent of Code 2020 - BaseA Style (Day 10)

AdamR_AYX — Thu, 10 Dec 2020 10:46:35 GMT

I think you can brute force if you reduce the problem on every iteration

Here is my iterative macro

Full solution at https://gitlab.com/adriley/adventofcode2020-alteryx/-/blob/master/day10-part2.yxmd

Re: Advent of Code 2020 - BaseA Style (Day 10)

OllieClarke — Thu, 10 Dec 2020 12:18:36 GMT

Struggled with Part 2, and found help on the adventofcode subreddit. Immediately tried to brute force it until I noticed the 'trillions'

workflowPart 1 iterative

Re: Advent of Code 2020 - BaseA Style (Day 10)

AkimasaKajitani — Thu, 10 Dec 2020 13:03:13 GMT

Day 10!

Part1 was very easy. But Part 2 is.... I couldn't have Iterative approach.
My approach is calculating Combination Numbers. It is similar to @OllieClarke 's approach.

I tried to make all pattern, but it was failed.
And then, I try to calculate combination numbers.

As anonymous user #1105310

Re: Advent of Code 2020 - BaseA Style (Day 10)

peter_gb — Thu, 10 Dec 2020 13:18:55 GMT

Revisited part 2 after some reddit research and the hint from @jdunkerly

-- A nice explainer here https://www.reddit.com/r/adventofcode/comments/ka9pc3/2020_day_10_part_2_suspicious_factorisation/

Still feels a little shonky though as it wouldn't automatically handle longer chains of 1's up to a 3.
I went through a few different approaches in the disabled container but got lost until seeking help on the maths/logic.

Re: Advent of Code 2020 - BaseA Style (Day 10)

patrick_digan — Thu, 10 Dec 2020 13:25:34 GMT

I went for a lot of multi-row formula tools...

Re: Advent of Code 2020 - BaseA Style (Day 10)

cgoodman — Thu, 10 Dec 2020 14:41:24 GMT

Day 10 part A felt more like a day 1 question.

Still working on Part 2, I am currently stuck down a rabbit hole of thinking there is a brute force binary solution to it by trying to generate a series of 1,0s between record 1 and 104 to act as a T|F flag and then to run my multi row. However that's too big, so trying to slim it down by spotting patterns, for example I know my start and end are fixed. and there are repeating 1,1,3 and 1,1,1,3s and know from experience with some of the previous AoCs now looking for patterns.

Finally got there with the second part.

Took the idea of finding the patterns using regexcountmatch and then unwinding the fact that 3,1,1 appears in 3,1,1,1. It did mean to get the right answer I needed to hard code for sole 1,1 which occurs at the start of my workflow.

Re: Advent of Code 2020 - BaseA Style (Day 10)

Galouzis — Thu, 10 Dec 2020 13:45:59 GMT

My solution was very similar to that of @jdunkerley79

Re: Advent of Code 2020 - BaseA Style (Day 10)

Greg_Murray — Thu, 10 Dec 2020 14:18:37 GMT

Mine is similar to others.

Re: Advent of Code 2020 - BaseA Style (Day 10)

NedHarding — Thu, 10 Dec 2020 15:08:01 GMT

This was much less of a programming problem and more of a maths problem. And **bleep** all of my UK friends for making me add the s to math! Anyway - super fun problem.

A little hint that isn't obvious at all looking at it at all - there is binary involved again!

Re: Advent of Code 2020 - BaseA Style (Day 10)

danilang — Thu, 10 Dec 2020 15:50:07 GMT

Non macro solution. Thanks @jdunkerley79 for the hint to part 2.

Continuing with my Amp exploration from yesterday, this solution runs slower in the Amp engine(0.8s) vs the original(0.3s). It probably has to do with the trade off between the overhead in analyzing the workflow for parallel processing and the speed increase gained. Since there are very few rows in the input data, the overhead vastly outweighs the performance gains. To investigate this more, I added a generate rows tool to the start to see where potential performance gains begin. In this very linear workflow, AMP starts to show benefits once the input consists of about 3.5M rows.

Dan

Re: Advent of Code 2020 - BaseA Style (Day 10)

NicoleJohnson — Thu, 10 Dec 2020 16:53:37 GMT

Couldn't have done this without your hints, @jdunkerley79. I knew there had to be a pattern but was having a hard time spotting it... I did mock it up after reading your suggestion, however, just to prove it out to myself... you're a wizard, my friend.

I did create a fabulous little macro that would have solved Part 2... if there weren't trillions of combinations. But thankfully, with James' tip, I was able to eventually figure this one out!

Cheers!

https://github.com/AlteryxNJ/AdventOfCode_2020

Re: Advent of Code 2020 - BaseA Style (Day 10)

balders-ie — Thu, 10 Dec 2020 17:45:06 GMT

[deleted]

apols for duplicating my post, need to make sure I'm on the right account, see below for my answer.

Re: Advent of Code 2020 - BaseA Style (Day 10)

Balders — Thu, 10 Dec 2020 18:15:57 GMT

I got a nice little use out of the tile tool there and [edit] some janky maths that doesn't hold for higher numbers now I've read the reddit thread. 😅

Workflow:

Calc for the multiplier [wouldn't work for n=6]

Re: Advent of Code 2020 - BaseA Style (Day 10)

Balders — Thu, 10 Dec 2020 20:20:13 GMT

I've now supersimplified it with a conditional Tribonacci

IF [Row-3:data] + 3 >= [data] THEN MAX([Row-3:ans],1) ELSE 0 ENDIF +
IF [Row-2:data] + 3 >= [data] THEN [Row-2:ans] ELSE 0 ENDIF +
IF [Row-1:data] + 3 >= [data] THEN [Row-1:ans] ELSE 0 ENDIF

Re: Advent of Code 2020 - BaseA Style (Day 10)

T_Willins — Thu, 10 Dec 2020 18:46:58 GMT

This took me back to math theory and patterns from college. What was hanging me up on part b is I was trying to apply the pattern below "1113" (count ones = 3). At and above that it is:

(3*Pow(2,[Count]-3))+1 Below 3, [Count]=2 is 2 and [Count] 1 is 1

Re: Advent of Code 2020 - BaseA Style (Day 10)

patrick_digan — Thu, 10 Dec 2020 18:51:38 GMT

@Balders Nice use of the tile tool, I could have replaced 2 multi rows with 1 tile in my workflow.