Advent Of Code Swift Template

This repository serves as a template for an Xcode project set up to solve the Advent of Code problems in Swift. No attempt is made to automate the fetching of inputs. It’s a simple MacOS command line project, meaning there are no resources bundled, so the inputs must be held in a directory and specified with a command line argument.

Command Line Arguments

The command line arguments when running in Xcode can easily be set by going to Product -> Scheme -> Edit Scheme... and clicking on the Arguments tab in the Run configuration.

  • Specify the path to the folder where the inputs can be found by passing in the -i argument. E.g. -i /path/to/inputs. Inputs should be saved in files matching the format day%d_input.txt, for instance day20_input.txt.
  • Specify the day to run using the -d argument. E.g. -d 4. If no specific day is found, all 25 days are run.


  • Xcode 13+


It’s a very simple architecture with a Day protocol adopted by various day classes. Each day has a part1 and a part2 function that take in an input and returns some CustomStringConvertible, meaning you can return an Int, String, Bool, etc. Templates are provided for each day’s unit tests as well to test parsing, algorithms, etc.

An example Day1.swift and Day1Tests.swift are provided to solve the 2020 Problem 1


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