AdventOfCode

Overview ¶

The AdventOfCode project contains my solutions for the Advent of Code series of puzzles from 2015 to 2019. Progress varies between these years, but I shall finish this project in due time.

Usage ¶

If a year or day is invalid, or if the puzzle for some day of some year has yet to be implemented, the program will panic.

./AdventOfCode [other flags] -year YEAR -day DAY -input FILE

For example:

./AdventOfCode [other flags] -year 2015 -day 4 -input inputs/2015_04.txt

Profiling flags ¶

There are three profiling flags available: -trace, -cpuprof, and -memprof. Only one of them may be turned on at one time, with -trace having leading priority. They will write their outputs to trace.out, cpu.pprof, and mem.pprof respectively in the current folder.

Glog flags ¶

This package uses the Google logging library https://github.com/golang/glog. A solver function may use glog to log what it's doing to Info or Warning. The user may set -stderrthreshold to modify the level of verbosity.

Structuring of packages ¶

This project contains several packages: those containing the solutions (which start with aoc), and utilities packages (in the internal folder).

The aoc20XX Packages are those that contain the solutions for the Day and the Year they are written. For example, the solution for Day 4 of Year 2015 is aoc2015.Day04, which is in day04.go in the aoc2015 folder. Each of these "Solver Functions" are written such that they take in a *bufio.Scanner, which contains the text for the puzzle input, and returns two strings answer1 and answer2, and an error.

// Day04 solves the fourth day puzzle "The Ideal Stocking Stuffer".
//
// Input
//
// A string of length 8 containing only the lowercase
// letters 'a' to 'z'. For example:
//
//	iwrupvqb
func Day04(scanner *bufio.Scanner) (answer1, answer2 string, err error) {
	// ...implementation
}

For some puzzles, I have written more than one solver function. These other solver functions are written as alternative solutions, but I believe that the "primary" one is the most optimal. For example, there is also an aoc2015.Day04ST, which is just like aoc2015.Day04 but is a single-threaded solution. Alternative solutions are only there in special cases, such as documenting single threaded solutions or using alternative algorithms. These are also benchmarked using my input as well as those from other people.

For some puzzles, answer1 or answer2 do not give the exact answer, but rather require a human to look at the output directly and infer the actual answer from there. These puzzles are often in the form of "your output will display an ASCII image containing a word which you should input". Parsing these outputs are difficult so I have left them be.

I have not written every Solver Function there is yet, and for those that have yet to be implemented, a dummy Solver Function is written that just throws an error that says "unimplemented".

These Solver Functions could not act alone, and thus would need the assistance of helper structs and functions. These Helpers are also visible in the .go files in their respective Day and Year, and each set of Helpers are unique to a certain Solver Function. While these Helpers are left unexported, they can still be viewed in godoc using ?m=all. Helper packages also exist in the aoc20XX folders wherein multiple puzzles in a year use a set of tools.

Most Helpers and all Solver Functions are tested using the internal package. The internal package is only meant to be used for testing. In the future, this may be deprecated so that the aoc20XX packages could stand alone. These tests also include the inputs that are given to me.

Each aoc20XX package will also have an AllSolutions in their solutions.go, which is a way to store all Solver Functions in one slice, which this Program imports to choose the correct Solver Function given a Day and a Year. Note that some of these functions are unimplemented.

The packages written can be used outside of this project, by importing the appropriate aoc20XX package.

Input file ¶

The program is designed to read from an input file which is the user's "puzzle input". Check the inputs/ folder in this repository for my inputs. In addition, I have also placed these inputs as strings in each package primarily for testing purposes.

If the puzzle input is not "valid", undefined behavior may follow. Often, the Solver function may throw out an error and the program's execution may halt. Othertimes, the Solver function may not care and parse the input as-is. The tests written mostly do not check for invalid inputs. Great care is taken so that none of the solver functions panic.

Each Solver Function should provide documentation on what the input file looks like.

License ¶

MIT License:

Copyright (c) 2019 janreggie

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.