Advent Of Code

Puzzles from Advent of Code solved using Go.

My goal is to resolve problems on release day. Then, I refactor my code in order to have clean code, even if it means losing slightly in performance.

Commands

• cd <year>/<day>/ to navigate to a specific day's directory,
• go run ./day<i>.go to run the solution for a particular day,
• go test to run unit tests.
• go test -bench . to run benchmarks.

2023

Execution time with :

• goarch: amd64
• cpu: AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx

Day	Go	Part1	Part2	Comment
1	**	0.039ms	1.51ms
2	**	0.44ms	0.47ms
3	**	0.42ms	0.55ms	Finding the numbers in the grid, then the symbols that are adjacent to them.
4	**	0.53ms	0.52ms
5	**	0.12ms	1.24ms	Using intervals, implementing the splitOn method to split the interval before shifting it.
6	**	0.002ms	47.2ms	Naive resolution, without calculating roots or binary search.
7	**	7.35ms	7.59ms	Using '*' instead of 'J' to represent jokers. Sorting with sort.Slice.
8	**	0.98ms	3.96ms	Using LCM (Least Common Multiple) (doesn't work for general inputs, works here because the cycle length on each path is the same).
9	**	1.20ms	1.21ms	Resolution without recursion.
10	**	6.11ms	30.6ms	Representation of a pipe by a set of directions. Using ray tracing for part 2. With visualization for part 2.
11	**	3.89ms	3.80ms
12	**	11.8ms	117ms	Using dynamic programming.
13	**	0.30ms	0.31ms	Using binary number to represent each line (in order to reduce execution time when comparing 2 lines).
14	**	2.30ms	914ms	Using memoization to avoid redundant cycles.
15	**	0.14ms	1.17ms
16	**	5.55ms	1217ms	Part 2 in brute force. With visualization for part 1.
17	**	519ms	1844ms	Using A* algorithm (Implementation of IntPriorityQueue in utils).
18	**	0.11ms	0.13ms	Using Shoelace formula and Pick's theorem.
19	**	1.07ms	2.06ms	Parsing with fmt.SscanfUsing. Using intervals for part 2.
20	*	15.6ms		TODO (Part 2 not yet started).
21	*	21.3ms		TODO (Reflection done, implementation to be done).
22	**	12.7ms	118ms	Settling bricks from bottom to top, knowing the bricks directly below and above it.
23	**	17.8ms	1310ms	Transforming the grid into a graph (directed for part 1 and undirected for part 2) using Breadth First Search, and then getting the length of the longest simple path using Depth First Search.
24	*	2.56ms		TODO (Part 2 : nonlinear system of 9 equations with 9 unknowns found, look for a solver in Go or linearize the system).
25	*	21.5ms		Separating the graph into 2 groups by calculating the shortest path between 2 vertices (with BFS), removing edges from this path, and repeating this 3 times (The minimum cut cardinality is 3 according to the puzzle). If there is no 4th path, the 2 vertices are in a different group and the new graph is cut, otherwise start again with a new vertex. Then finding the vertices belonging to the first group using BFS.
Total	46*			4 stars missing: parts 2 of days 21, 22, 24 (and 25).