2020 was my first year to be introduced to Advent of Code, and I'm officially in love! This repository houses my work/solutions to the Advent of Code 2020 puzzles. The structure is one folder per day, labled with that day's date/label. The initial implementation for each solution is in R, because that's the language I'm most comfortable with. Each folder contains the puzzle input in an input.txt file, and potentially some optional test inputs in test_input{n}.txt files. I've broken the R solutions into two files, exercise_1.R and exercise_2.R. There are one or two where I tried different approaches and so have an exercise_1b.R or some such.
I've blogged my approaches to the R version of each solution here: Advent of Code Blog. Each one includes not only the code but some commentary on the thinking behind the approach and my thoughts about the puzzles in general.
I found these puzzles to be interesting and diverse enough, and at a reasonable enough difficulty level, to make a really good set of exercises for learning new languages. In particular, I'm working on picking up Rust, so each day is going to start being divided into an R and a rust folder. The R folder will look just like the days that haven't been converted, the rust folder will have a crate from cargo new with *.rs files containing the solution code.
I've finished implementing all 25 Days in Rust. As I suspected, this was a really good set of problems to work through as I learned the language. I now feel competent (if not exactly excellent) at writing Rust code. I timed the code execution for all 25 days on my laptop, and Rust is able to chew through both parts of all 25 days in less that 1.14 seconds. This is a vast improvement over the R run times, though I do have to admit I find it much easier to reason through the puzzles in R (and a few of the days that I solved with R-specific features like matrices/arrays, environments, or data frames took some extra thought-work). In the end, I've learned a lot and feel like I can go and be productive with Rust, which is everything I could have hoped for.