Speed-optimized solutions for challenges found on https://adventofcode.com/ in R, and in Rust / C++ for easy to implement bruteforce challenges.
Year 2020 runs in 1.2 sec, with days 15, 23 and 25 written in Rust, and approximatively 9 sec with only R code.
Year 2021 runs in 13 sec (only R).
Detail of runtime is present in each folder.