Advent of Code 2025 Day 2 (BaseA Style)

[AlteryxCommunityTeam]

Discussion thread for day 2 of the Advent of Code - https://adventofcode.com/2025/day/2

[aiahwieder]

Brute force but it worked!

Anybody found a good way to

Spoiler

use the IterationNumber constant in a Regex Tokenize expression?

[clmc9601]

Thankful for a 30-minute problem! This doesn't feel like a very elegant solution, but at least it's macro-free...

Spoiler

Generate Rows and regex, classic AoC. I'm really curious to see if anyone solved it completely in regex. 

I used regex_match and regex_countmatches to make sure the entire pattern is composed of the same subcomponents and that each subcomponent is listed >1 times.

[clmc9601]

@aiahwieder, my thoughts:

Spoiler

While the Regex tool doesn't take values from variables easily, you can probably reverse engineer your solution to use regex_replace (add delimiter) in a Formula tool in combination with the Text to Columns tool (split to rows/columns). The regex functions in an expression editor should allow any value from variables as long as they're input as a string.

[mmontgomery]

Day 2

Spoiler

Part 1 was straight forward to generate rows then do a left/right logic based on length.
Part 2 I created separate logic for each sub length: 1, 2, 3, 4, 5 to match on,union then get rid of duplicates

[aiahwieder]

Might try this out and report back; fortunately the data set was strings no longer than 10 characters, but it made me long for an iterative approach!

[lwolfie]

Spoiler

Had to actually work, so I missed the posting. Still fun and glad I got my 2 stars again!

[DanFlint]

Spoiler

Ended up solving part 2 when trying to figure out the RegEx for part 1

[Hub119]

Day 2 Solve

Spoiler

After the input parsing and generating the numbers that needed checked (also while solving did the quick range check first to determine how many records I would be creating... no need to blow up another computer), for Part 1 I went with a simple filter to records that were an even number of characters and matched the left half to the right half.  For Part 2, while a single RegEx match function is all that is really needed, it took me a bit longer than I'd like to sort out the right RegEx to actually do so... I blame the Advent of Whiskey calendar that has been going alongside this year's event #HardMode

[mkeiffer]

Spoiler

 RegEx is my hero!