Advent of Code 2021

Advent of Code 2021 ! I’m trying Rust this year, let’s see how it goes :)

For reference, I only know Python and I have absolutely no experience with typed languages nor with compiled languages.

What I learned

• Day 1: Use of cargo, a rust project’s structure, the cargo.toml file and the [[bin]] keyword.
• Day 2: The difference between a String and a str, the option type and the unwrap() method, a first try at simple pattern matching and string splitting with lines() and split_whitespace() methods.
• Day 3: First brush with the borrow checker and lifetimes, the definition of function with the fn keyword, use of Vec<&str>.
• Day 4: Using HashMaps, the creation of custom structs, const and enums, using the impl and pub keywords, #[derive(PartialEq)], break and continue statements can be scoped to target outer loops, separating code in different files and using crate:: and mod, using a constructor to initiate members of our structs, the retain method for vectors, dereferencing a value with *.
• Day 5: Deriving more stuff like Hash, how to write and run tests, writing a function returning Results (and the difference between returning a result and panicking).