Advent of Code

Advent of Code Site

I love Advent of Code, but I have never gotten an opportunity to code the solutions in real time (daily). While I write code for work, and much of that ends up performance-optimized, I rarely think about computer science algorithms. Instead, much of my programming ends up working with libraries and interfacing with APIs. The Advent of Code puzzles provide an opportunity to go back in time, to think about lower-level approaches to problems. Some work friends and I have private leaderboards or vow to work with a specific language to solve puzzles, but I cannot compete with speedcoders. I mean, I have seen times posted on the global leaderboard before I have fully grokked the problem to solve.

In 2025, I decided to earn all the stars, completing puzzles in order, starting with the first ones from 2015. And, I decided to solve them all using the Go programming language. These live in the /go directory, which contains a Makefile for build, execution and testing.

Build and Execution

> make build && ./aoc --help
Advent of Code puzzles solved with Go. Use `make` to see build and execution options.

Usage:
  make YEAR=2015 DAY=1 run [flags]

Flags:
  -d, --day int    Day of the puzzle
  -h, --help       help for make
  -y, --year int   Year of the puzzle

Parsing the command line arguments comes from the Cobra package (see /cmd for more information).

You do not need to build the executable in order to solve a specific day. Instead, use make run.

> make YEAR=2016 DAY=7 run
Year=2016 Day=07 Part 1: 105 (13.804417ms)
Year=2016 Day=07 Part 2: 258 (10.719625ms)

Tests

Using make test will provide test and coverage output. All functions adhere to a naming standard to easily display test coverage for a specific day.

> make test | grep y16d07.go | column -t
github.com/bandarji/aoc/adventofcode/y16d07.go:16:  y16d07              100.0%
github.com/bandarji/aoc/adventofcode/y16d07.go:35:  y16d07ParseAddress  100.0%
github.com/bandarji/aoc/adventofcode/y16d07.go:54:  y16d07IsTLS         100.0%
github.com/bandarji/aoc/adventofcode/y16d07.go:64:  y16d07HasABBA       100.0%
github.com/bandarji/aoc/adventofcode/y16d07.go:75:  y16d07IsSSL         100.0%
github.com/bandarji/aoc/adventofcode/y16d07.go:87:  y16d07FindABAs      100.0%

Progress

Year	Stars	Notes
2024	33	Go
2023	47	Go
2022	25	Go, Rust and Python
2021	23	Go and Python
2020	19	Python - first year to join
2019	2	C - wrote solution in 2020
2018	0	Did not participate
2017	0	Did not participate
2016	23	Go
2015	50	Go, Rust and Python

2015 Complete!