Advent of Code 2025

These are my advent of code 2025 solutions!

AI was used to assist for the following tasks:

• Day 9, Challenge 2 - main2.py - minor change to check_rectangle function ONLY. See comment on line 53,54
• Day 10, Challenge 2 - main.py - jolts_linalg function which uses z3-solver. I was totally unfamiliar with this. Prior to this, I tried several bfs optimisations but they did not work. However, I am learning how this works. I also looked into other manual linear algebra techniques to build up my understanding, and will be implementing those.
• Day 11, Challenge 2 - main.py - using @lru_cache in dfs function was recommended by AI. I was totally unaware of this and this was something new I learnt today! The graph logic was mine. However, I am still trying to implement more optimised versions which don't directly use lru_cache.

For Day12, there was only one challenge, and the current code only reflects the code necessary to pass the test cases (the input test cases don't account for cases where we may need to rotate or flip!). However, for my own understanding, I will definitely try to figure out how to solve these problems when we do need to rotate/flip.

This is the first time I have completed the entire adventofcode and it has been great! I have learnt so much and I look forward to improving my solutions as well as attempt past year questions!