Advent of Code 2023

This repository contains my solutions for the Advent of Code 2023 challenge.

Language

I am using C# for this year's challenge. I'd consider myself proficient in C#, but on a day to day basis I don't use it as much and would just like to get more practice with it.

Structure

Each day's solution is contained in a separate folder. Each folder contains:

• A PROBLEM.md file containing the problem description.
• A INPUT.txt file containing the input for the problem.
• A dotnet console application containing the solution.
• An xUnit test project containing unit tests for the solution.

Prerequisites

• .NET 8.0

Running the Solutions

To run the solutions, navigate to the solution folder and run the following command:

dotnet run -- <path-to-input-file>

Or for part 2 solutions

dotnet run -- <path-to-input-file> part2

You can also build the projects and run the executables directly.

dotnet build
./bin/Debug/net8.0/<project-name> <path-to-input-file>

Challenges

Day	Problem	Solution	Status	Notes
01	Problem	Solution	✅	The trickiest part here was accounting for overlapping digit words.
02	Problem	Solution	✅	The key to me here was to parse the input into a useful model.
03	Problem	Solution	✅	The edge case that got me here was lines ending with a part number.
04	Problem	Solution	✅	Part 2 gets out of hand quickly with just 200 cards.
05	Problem	Solution	✅	I brute forced part 2 using parallelism. I know shame.
06	Problem	Solution	✅	Thank goodness part 2 was not like 5's part 2. 😅
07	Problem	Solution	✅	What took me longest here was I missed a case when jokers are wild and there are three groups of cards.
08	Problem	Solution	✅	Got to implement a least common multiple algorithm for part 2.
09	Problem	Solution	✅	Part 1 took me unnecessarily long. The bug was summing a line to check for all zeros is bad idea when negative numbers are involved.
10	Problem	Solution	✅	So...my solutions are rather slow, but they work. Part 2 appears to have a mathematical solution, but scanning is what I came up with on my own.
11	Problem	Solution	✅	Expanding the universe was fine in part 1, but part 2 showed I actually needed to calculate the expansion instead of expanding the input.
12	Problem	Solution	✅	This one stretched my skills. I needed lots of help from the interwebz.
13	Problem	Solution	✅	This solution is the one I think I'm most proud of so far.
14	Problem	Solution	⌛
15	Problem	Solution	⌛
16	Problem	Solution	⌛
17	Problem	Solution	⌛
18	Problem	Solution	⌛
19	Problem	Solution	⌛
20	Problem	Solution	⌛
21	Problem	Solution	⌛
22	Problem	Solution	⌛
23	Problem	Solution	⌛
24	Problem	Solution	⌛
25	Problem	Solution	⌛