Advent of Code

Advent of Code is an annual "mental gym" in which increasigly difficult challenges force you to optimize your code to remain within reasonable execution times. In 2025, I chose to use C# when I partook for the first time, focussing on performance as a first priority.

The Technical Challenge

The difficulty curve of AoC is steep. The second parts of each puzzle often require moving beyond "brute force" to more advanced concepts:

• Graph Theory: Implementing Dijkstra and A* for pathfinding puzzles.
• AABB: Instead of checking entire grids, often it is better to make coordinate based checks instead.
• Parsing: Using Regex and custom parsers to handle complex input strings.

What I Gained

• Performance Optimization: Several puzzles required reducing execution time from minutes to milliseconds through better data structure selection.