Advent of Code is an Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.
Link to event: https://adventofcode.com/2020
To run a solution, cd into examples directory and invoke the program with Cargo:
Example to run solution for day1:
$ cd examples
$ cargo run --example day_1
If you have questions about the code, feel free to open an issue and ask away!