Advent of Code notebooks/worksheets, partly with input files.
Python notebooks created with Google Colaboratory.
Scala worksheets created with Intellij IDEA with Scala plugin.
(Days 6 to 24 only) - Input files are referred 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 and 2024 below (also need to change the code to read from the Google Drive location.)
Input files for AoC 2021/ and 2024/ are expected in your Google Drive in My Drive/AoC/2021/ and My Drive/AoC/2024/.
Colab must be given permission to mount your Google Drive.
Used Scala worksheets in IDEA instead of Python notebooks. One per day. Inputs can be found in 2022/src/main/resources.
See 2021/2024 above.
Input files not downloaded, the notebook 2025/aoc2025.ipnb contains code to download the input data directly from AoC website using your session cookie. There is also a utility to find all test input data candidates from the problem description page. You can run it once to display all candidates, then run it again with the desired candidate index.