Advent of Code 2025

Update #1: It's that time of the year again... So let's go!!

Update #2: Regex backreferences for the win!

Update #3: 1/3 of this year's (shorter) AOC done! So far nice and fun puzzles as always. Let's see how the rest of the days go!

Update #4: Went to the countryside for the weekend to make some sausages, so I wasn't solving puzzles on Friday and the weekend. Today I solved days 5–8, which puts me back on track!

Update #5: Found out today about z3 library which is great in theorem proving and constraint solving and SMT problems.. 2 days left!

Update #6: Day 11 was not that hard, classic graph traversal problem. Part 2 though had pretty deep paths. I forgot about rule of product that can be applied to count the paths between each node pair and then multiply the results... even though I seen many AoC problems in the past that were solved that way.

Update #7: On another note, tomorrow is the last day, I really like this new 12 day format, even though some days were tough it overall much less stressful in busy December period.

Update #8: And that's a wrap! Managed to finish all the puzzles this year! It has been a ride for this last 10 years I have been doing AoC. A lot of good memories, learning new languages, new techniques and algorithms. After 10 years I need a break but I will always be following /r/adventofcode and support the community. 🎄🎄