PHP solutions to https://adventofcode.com/ for 2021.
The tasks are split into days (folders) and parts (2 parts per puzzle). I have done my best to comment my code with my thought process to facilitate following the logic when coming back to this at a later point.
The test input for each day is added as 2 files into each day's folder. "testinput.txt" is the "official" small test set given on the puzzle question. "input.txt" is the actual test input which is personalised for each user of Advent of Code.
The original questions as well as the answers produced by the given code files can be found in each day's "puzzle.txt".