🎄 Advent of Code 2022 🎄

This repository contains my solutions for Advent of Code 2022, my second year of participation.

What is Advent of Code?

Advent of Code is a series of small programming puzzles created by Eric Wastl. Every day from December 1st to 25th, a puzzle is released alongside an engaging fictional Christmas story. Each puzzle consists of two parts, the second of which usually contains some interesting twist or changing requirements and is only unlocked after completing the first one. The objective is to solve all parts and collect fifty stars ⭐ until December 25th to save Christmas.

Many users compete on the global leaderboard by solving the puzzles in an unbelievably fast way in order to get some extra points. Personally, I see Advent of Code as a fun exercise to do during the Advent season while waiting for Christmas. I often use it to learn a new programming language (like I did in 2021 with C#) or some advanced programming concepts. I can only encourage you to participate as well - of course in a way that you find fun. Just get started and learn more about Advent of Code here.

About This Project

The solutions for Advent of Code 2022 were originally developed using .NET 7 and C# 11 at the time. Since then I have taken some time to update them to more recent versions (.NET 9 and C# 13), which allowed me to take advantage of new language features and modern data structures that either did not exist yet or I did not know about (as I was still learning the whole ecosystem). These include expression bodies (=>), collection expressions ([...]), target-typed new(), Span<T> and ReadOnlySpan<T>, types of the System.Collections.Immutable or System.Collections.Frozen namespaces and much more.

For this project and in general when developing software, I strive to produce readable and well documented source code. However, I also enjoy benchmarking and optimizing my code, which is why I sometimes implement a less idiomatic, yet more efficient solution at the expense of readability. In those situations, I try to document my design choices with analogies, possible alternative solutions and sometimes little sketches to better illustrate the way a piece of code works.

The general structure of this project is as follows:

Day 1 - Calorie Counting/
    Resources/
        .gitkeep
    Source/
        Benchmark.cs
        CalorieCounting.cs
    Day 1 - Calorie Counting.csproj
Day 2 - Rock Paper Scissors/
    Resources/
        .gitkeep
    Source/
        Benchmark.cs
        RockPaperScissors.cs
    Day 2 - Rock Paper Scissors.csproj
...
Day 25 - Full of Hot Air/
    ...
.gitignore
Advent of Code 2022.sln
LICENSE
README.md

On the top level, the solution file contains 25 standalone projects for the days of the Advent calendar, organized into separate directories. Each one provides a corresponding .csproj file that can be opened in Visual Studio. In addition, there are the usual Source and Resources directories, the latter of which contains the puzzle description and my personal input for that day. However, as requested by the creator of Advent of Code, these are only present in my own private copy of the repository and therefore not publicly available.

If you're posting a code repository somewhere, please don't include parts of Advent of Code like the puzzle text or your inputs.

As a consequence, you will have to provide your own inputs for the days, as described in more detail in the following section.

Dependencies And Usage

If you want to try out one of my solutions, simply follow these steps below:

0. Make sure you have .NET 9 or a later version installed on your machine.

1. Clone the repository (or download the source code) to a directory of your choice.

   git clone https://github.com/Piwimau/Advent-of-Code-2022 "./Advent of Code 2022"
   cd "./Advent of Code 2022"

2. Put your input for the day in a file called input.txt and copy it to the appropriate resources directory. You can get all inputs from the official website if you have not downloaded them already.

   cp input.txt "./Day 1 - Calorie Counting/Resources"

3. Nagivate into the appropriate day's directory.

   cd "./Day 1 - Calorie Counting"

4. Finally, run the code in release mode to take advantage of all optimizations and achieve the best performance.

   dotnet run -c Release

   Optionally, specify an additional flag --benchmark to benchmark the relevant day on your machine. Note that in this mode no output for the results of the solved puzzle is produced.

   dotnet run -c Release --benchmark

If you have Visual Studio installed on your machine, you may also just open the provided solution file and proceed from there.

Benchmarks

Finally, here are some (non-scientific) benchmarks I created using the fantastic BenchmarkDotNet package and my main machine (Intel Core i9-13900HX, 32GB DDR5-5600 RAM) running Windows 11 24H2. All benchmarks include the time spent for reading the input from disk, as well as printing the puzzle results (although the output is written to TextWriter.Null when benchmarking, which is effectively a no-op and rather fast).

Day	Min	Max	Mean	Median	Standard Deviation
Day 1 - Calorie Counting	0.069 ms	0.071 ms	0.069 ms	0.069 ms	0.001 ms
Day 2 - Rock Paper Scissors	0.235 ms	0.239 ms	0.237 ms	0.236 ms	0.001 ms
Day 3 - Rucksack Reorganization	0.318 ms	0.337 ms	0.329 ms	0.330 ms	0.005 ms
Day 4 - Camp Cleanup	0.137 ms	0.140 ms	0.139 ms	0.139 ms	0.001 ms
Day 5 - Supply Stacks	0.170 ms	0.174 ms	0.173 ms	0.173 ms	0.001 ms
Day 6 - Tuning Trouble	0.028 ms	0.029 ms	0.029 ms	0.029 ms	0.000 ms
Day 7 - No Space Left On Device	0.185 ms	0.188 ms	0.186 ms	0.187 ms	0.001 ms
Day 8 - Treetop Tree House	0.513 ms	0.539 ms	0.523 ms	0.521 ms	0.008 ms
Day 9 - Rope Bridge	0.943 ms	0.964 ms	0.954 ms	0.954 ms	0.006 ms
Day 10 - Cathode-Ray Tube	0.022 ms	0.023 ms	0.022 ms	0.022 ms	0.000 ms
Day 11 - Monkey In The Middle	3.140 ms	3.190 ms	3.166 ms	3.169 ms	0.014 ms
Day 12 - Hill Climbing Algorithm	29.744 ms	31.156 ms	30.622 ms	30.613 ms	0.353 ms
Day 13 - Distress Signal	0.420 ms	0.432 ms	0.426 ms	0.426 ms	0.003 ms
Day 14 - Regolith Reservoir	58.409 ms	61.027 ms	59.449 ms	59.324 ms	0.764 ms
Day 15 - Beacon Exclusion Zone	133.735 ms	140.129 ms	136.489 ms	135.957 ms	1.777 ms
Day 16 - Proboscidea Volcanium	730.019 ms	775.538 ms	750.803 ms	750.714 ms	13.966 ms
Day 17 - Pyroclastic Flow	2.056 ms	2.144 ms	2.091 ms	2.091 ms	0.022 ms
Day 18 - Boiling Boulders	1.028 ms	1.074 ms	1.054 ms	1.052 ms	0.011 ms
Day 19 - Not Enough Minerals	131.870 ms	141.179 ms	136.107 ms	136.157 ms	2.409 ms
Day 20 - Grove Positioning System	34.480 ms	35.278 ms	34.902 ms	34.911 ms	0.260 ms
Day 21 - Monkey Math	1.670 ms	1.744 ms	1.707 ms	1.706 ms	0.027 ms
Day 22 - Monkey Map	0.553 ms	0.591 ms	0.570 ms	0.573 ms	0.011 ms
Day 23 - Unstable Diffusion	425.963 ms	436.287 ms	430.321 ms	430.350 ms	2.572 ms
Day 24 - Blizzard Basin	193.843 ms	208.269 ms	201.307 ms	201.106 ms	3.405 ms
Day 25 - Full of Hot Air	0.037 ms	0.038 ms	0.038 ms	0.038 ms	0.000 ms
Total	1749.587 ms	1840.780 ms	1791.713 ms	1790.847 ms	25.618 ms

License

This project is licensed under the MIT License. Feel free to experiment with the code, adapt it to your own preferences, and share it with others.