Advent of Code 2021

These are my Advent of Code 2021 solutions written in Scala 3, Haskell, Python and Rust.

Day	Title	L1	L2	L3	L4
01	Sonar Sweep	Scala	Haskell	Python	Rust
02	Dive!	Scala	Haskell	Python	Rust
03	Binary Diagnostic	Scala	Haskell	Python	Rust
04	Giant Squid	Scala	Haskell	Python	Rust
05	Hydrotermal Venture	Scala	Haskell	Python	Rust
06	Lanternfish	Scala	Haskell	Python	Rust
07	The Treachery of Whales	Scala	Haskell	Python	Rust
08	Seven Segment Search	Scala	Haskell	Python	Rust
09	Smoke Basin	Scala	Haskell	Python	Rust
10	Syntax Scoring	Scala	Haskell	Python	Rust
11	Dumbo Octopus	Scala	Haskell	Python	Rust
12	Passage Pathing	Scala	Haskell	Python	Rust
13	Transparent Origami	Scala	Haskell	Python	Rust
14	Extended Polymerization	Scala	Haskell	Python	Rust
15	Chiton	Scala	Haskell	Python	Rust
16	Packet Decoder	Scala	Haskell	Python	Rust
17	Trick Shot	Scala	Haskell	Python	Rust
18	Snailfish	Scala	Haskell	Python	Rust
19	Beacon Scanner	Scala	Haskell	Python	Rust
20	Trench Map	Scala	Haskell	Python	Rust
21	Dirac Dice	Scala	Haskell	Python	Rust
22	Reactor Reboot	Scala	Haskell	Python	Rust
23	Amphipod	Scala	Haskell	Python	Rust
24	Arithmetic Logic Unit			Python
25	Sea Cucumber	Scala	Haskell	Python	Rust

Remarks

• Scala solutions are short and concise, be sure to check them out.
• The solutions are self contained, they can easily be executed as shown in the next section. This also makes them just a bit cluttered because the parsing and the part selection are inside the same file.
• Both parts of each problem are solved in the same file, this requires a bit of generalization to solve both parts with almost the same code, and makes the code longer than other solutions.
• These are not the shortest or fastest solutions, but they are readable and show the key ideas for solving each problem and how to translate them to each different language.
• The Python solutions are a bit clunky because these are the ones I code first.
• The solutions in Rust are not so good because this is the first time I use Rust for this kind of problems. It gets better day by day, but don't expect amazing code.

Running the solutions

The solutions are self-contained and should run easily using the appropriate interpreter/compiler for each language, keeping the following considerations in mind:

• Input is taken from standard input.
• Either 1 or 2 must be passed as arguments to choose which part to run.

Scala 3

For example, to run the Scala solution for the second part of the first day, you can use the following command:

cat day01/test01.txt | scala day01/Day01.scala 2

Haskell (>= 8.10)

No other libraries apart from base, containers and mtl are used, they should be installed by default.

cat day01/test01.txt | runghc day01/Day01.hs 2

Python (>= 3.8)

Only numpy is used apart from the standard library.

cat day01/test01.txt | python3 day01/Day01.py 2

Rust (nightly >=1.62)

To run a Rust solution you must first compile it and then run the resulting executable:

rustc day01/Day01.rs
cat day01/test01.txt | ./Day01 2