Advent of Code 2025

This repository contains solutions for Advent of Code 2025 challenges. Each day's solution is stored in its own folder under src/dayX/.

Setup

1. Clone the repository

To clone the repository, run:

git clone https://github.com/davidebrognoli/adventofcode2025

Then navigate into the project folder:

cd adventofcode2025

2. Install dependencies

To install the required dependencies, run:

npm install

This will install Vitest for testing and any other dependencies required for the challenges.

Input Files

⚠️ Important: Following Advent of Code guidelines, the input.txt files are not committed to this repository to respect the terms of service. You will need to:

1. Create your own input.txt file in each day's folder (e.g., src/day1/input.txt)
2. Copy your personal input from the Advent of Code website for each day
3. Place it in the corresponding day folder before running the solutions

This ensures compliance with Advent of Code's request to not redistribute puzzle inputs.

Running the code

You can execute the solution for each day by using the following command:

npm start X

Where X is the day number (e.g., 1 for Day 1, 2 for Day 2, and so on).

Example:

To run the solution for Day 1, you can use:

npm start 1

This will execute the code in src/day1/index.js.

Testing

To run the tests for the solutions, use Vitest. You can run the tests with:

npm test

For a single run without watch mode:

npm run test:run

Alternatively, you can run specific tests with:

npx vitest run <test-pattern>

Folder Structure

adventofcode2025/
├── src/
│   ├── day1/
│   │   |── index.js         # Solution for Day 1
|   |   └── input.txt        # Input file for Day 1
│   ├── day2/
│   │   └── index.js         # Solution for Day 2
|   |   └── input.txt        # Input file for Day 2
│   |── ...
│   ├── utils.js             # Utility functions (e.g., input parsing)
├── run.js                   # Script to launch solutions for specific days
├── package.json             # Project configuration
├── test/
│   ├── day1.test.js         # Vitest tests for Day 1
│   └── ...
└── README.md                # This file
└── LICENSE                  # License

License

This project is licensed under the ISC License - see the LICENSE file for details.