horotw / adventofcode

Some solutions to the Advent of Code (AOC) puzzles.

🎄 Advent of Code 2021 🎄

Summary

This year I will post my solutions to the Advent of code, even though I think they are nothing special. I'm also writing my bachelor thesis right now, so I'm not sure if I'll do all the puzzles - but we'll see 😎.

Overview

Day	Name	Status	Notes
01	Sonar Sweep	⭐⭐	I think the pandas solution looks nice (a one liner each 😎) - also there is a nice trick in it that shows that the puzzle is solvable without an sliding window 😉.
02	Dive!	⭐⭐	The solution was really straight forward and only little code was needed.
03	Binary Diagnostic	⭐⭐	I did some beautiful (in my opinion not really) python magic
04	Giant Squid	⭐⭐	Here the python magic was nice 😊 - also I used a class for the board.
05	Hydrothermal Venture	⭐⭐	This was just fun 😊 - I wanted to avoided creating a line or a point class - so I made heavy use of tuples and list comprehensions
06	Lanternfish	⭐⭐	A little growth simulation was fun and I learned something about the defaultdict.
07	The Treachery of Whales	⭐⭐	Ahh this was cool - the computational complexity was greatly reduced (from n³ to n²) after finding an explicit formula for the sum of the first n numbers! I learned that these numbers are called triangular numbers. - nice refresher in finite series - a dynamic programming approach would have also reduced the time complexity but would have increased the storage complexity... and I wanted to use the explicit formula since I found one 😁 - I added a smarter way where the complexity is even much lower (avg: 807μs vs 280ms)
08	Seven Segment Search	⭐⭐	Was easier than I thought in the beginning. - would have been far more complex if not always all numbers would be there, then I had written an algorithm that uses permutations and tries to find an solution to the problem - but the puzzle was fun, even with an hard codable algorithm
09	Smoke Basin	⭐⭐	I found a really nice way of doing this puzzle by heavily leveraging scipy in particular the generic_filter and the label functions 🤩😍
10	Syntax Scoring	⭐⭐	reduce the reduce function was the mvp in this challenge. At least for me ^^ (the for else was also not bad) - This time it felt like I'm a step closer to a pythonic coding style 🙂 (a style that leverages Python's features to write code that is readable and beautiful)
11	Dumbo Octopus	⭐⭐	generic_filter ftw 🤣 - I also did a small visualization on the branch visualizations - the visualization can be also found as a video on youtube
12	Passage Pathing	⭐⭐	I failed again for memory views vs copies .... 🙈 yeah that happens 🤣
13	Transparent Origami	⭐⭐	A friend of mine had an bug in his input.. not really a bug more like an edge case that my input lacked... And yes my code does not work for an fold where the first half is smaller than the second - but as far as I can tell this was never needed... but for completeness it would be desirable ^^
14	Extended Polymerization	⭐⭐	For solution 1 I created a linked list that is iterable but that was of course not nearly enough for solution 2. Solution 2 is just hacked together ... maybe later on the day I will revisit this puzzle. ^^
15	Chiton	⭐⭐	With the networkx library it was doable in just a few lines of code - but the docu of networkx could be "more verbose" 😄
16	Packet Decoder	⭐⭐	That was fun but it was also the challenge that took the most time ^^ so many small silly bugs 🙈
17	Trick Shot	⭐⭐	I'm not really proud of the solution because I brute forced instead of using the superposition principle .... but hey I found the solution and it only took me a few minutes 🤣 (code executes in a second or two)
20	Trench Map	⭐⭐	The generic filter does it all ^^
21	Dirac Dice	⭐⭐	With a cache this was quite fast - I just have to remember that dimensions should not interfere with each other 🙈 (I summed the scores in the for loop - that was a stupid mistake that took me too long to see) - but the puzzle was fun 😊