Eric's Advent of Code 2021 Solutions

The Blog

I've blogged my approaches to the Julia 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.

Project Structure

This year, I plan on tackling AoC with Julia. I've dabbled a bit with Julia off and on over the past year, and this seemed like a golden opportunity to really put the langauge through it's paces. Because I know myself, I'm leaving room in the top level of this project to accommodate other languages as I have time/it strikes my fancy. For now, though, there's just JuliaAdventOfCode.

Julia Project

The Julia project structure looks like this:

JuliaAdventOfCode
├─inputs
│ └─DayXX
│   ├─input.txt
│   └─test.txt
├─src
│ ├─DayXX
│ │ ├─DayXX.jl
│ │ ├─Part01.jl
│ │ └─Part02.jl
│ ├─Benchmark.jl
│ ├─JuliaAdventOfCode.jl
│ └─RunAll.jl
├─tests
│ ├─DayXXTests.jl
│ └─runtests.jl
├─Manifest.toml
└─Project.toml

With the JuliaAdventOfCode package activated (see below):

• Get the results for all days with julia src/RunAll.jl
• Get the results for a single day with julia src/RunAll.jl -d 1
• Get the benchmarks for all days with julia src/Benchmark.jl
• Get the benchmarks for a single day with julia src/Benchmark.jl -d 1
• Run the tests with julia test/runtests.jl from the terminal
  • Alternatively, you can run the tests in the REPL in Pkg mode

For Day 1, that looks like:

❯ julia src/RunAll.jl -d 1

Advent of Code 2021 Results:

Day 01
├─ Part 01: 1583
└─ Part 02: 1627

❯ julia src/Benchmark.jl -d 1

Julia Advent of Code 2021 Benchmarks:

Day 01:
├─ Part 01:  2.987 μs (5 allocations: 20.31 KiB)
└─ Part 02:  4.561 μs (6 allocations: 36.06 KiB)

Note on Julia project activation

To conveniently use the commands listed above, add the following to your /.julia/config/startup.jl:

using Pkg
if isfile("Project.toml") && isfile("Manifest.toml")
    Pkg.activate(".")
end