Advent of Code notebooks/code snippets with input files.
Notebooks created with Google Colaboratory - https://colab.research.google.com/.
2020 (days 6 to 24) - Input files are refered to as input.txt for all days. So either the input file for each day of AoC 2020/ needs to be uploaded to colab runtime root dir as input.txt or you upload all files and change the notebook code to read input<day>.txt rather than just input.txt. You may also upload all files to Google Drive and mount Google Drive as described for 2021 below (also need to change the code to read from the Google Drive location.)
2021 - Input files for AoC 2021/ are expected in your Google Drive in My Drive/AoC/2021/ and Colab must be given permission to mount your Google Drive.