You can definitely get some incredibly elegant and fast solutions using Rust. Check out timvisee's AoC 2020 [0]. It honestly had a significant impact on my personal style.
To be clear, I don’t compete for the leaderboard or code golf. But I do try to write elegant code that’s performant.
AoC is a great way to learn a new language. I try to solve the puzzles entirely on my own. Then I check the Reddit solutions thread and Ctrl-F my language. It’s a great way to learn new tricks, libraries, or just idiomatic language style.
And using Rust for AoC turned me into a certified fan. Rust iterators are really great compared to C++. They’re like C# linq but better. The itertools crate is super helpful.
[0]: https://github.com/timvisee/advent-of-code-2020