Advent of Code 2025

꒷꒦︶꒷꒦︶ ๋ ࣭ ⭑꒷꒦⋆꙳•❅‧*₊⋆☃︎‧❆₊⋆❅𖢔. ݁₊⊹. ݁₊ ݁.𐂂꙳⋆𐙚❅⋆❆.ೃ࿔❆.ೃ࿔:･*❆. ݁₊ ⊹ ₊ ݁.₊⋆⋆꙳·̩̩͙❅*̩̩͙‧͙⋆**𓃴𓃙𓃠𓃥𓃚꒷꒦︶꒷꒦︶ ๋ ࣭ ⭑꒷꒦

Solutions for Advent of Code 2025 puzzles.

Project Structure

advent-of-code-2025/
├── day_1/
│   ├── solution.js
│   └── input.txt
├── day_2/
│   ├── solution.js
│   └── input.txt
├── day_X/
│   ├── solution.js
│   └── input.txt
└── README.md

Days Completed

❄️ Day 1: Secret Entrance ⤷ ˎˊ˗

• Part 1: Count the number of times the dial points at 0 after each rotation

• Part 2: Count every time the dial passes through 0 during any rotation

  Solution (❛ ֊ ❛)

☃︎ Day 2: Gift Shop ⤷ ˎˊ˗

• Part 1: Find invalid product IDs that are a pattern repeated exactly twice

• Part 2: Find invalid product IDs where any sequence of digits is repeated at least twice

  Solution (❛ ֊ ❛)

☃︎ Day 3: Lobby ⤷ ˎˊ˗

• Part 1: Find the maximum joltage by selecting exactly 2 batteries from each bank

• Part 2: Find the maximum joltage by selecting exactly 12 batteries from each bank (while maintaining digit order)

  Solution (❛ ֊ ❛)

🎄 Day 4: Printing Department ⤷ ˎˊ˗

• Part 1: Count rolls of paper (@) that can be accessed by a forklift (fewer than 4 adjacent rolls)

• Part 2: Simulate the removal process and count the total number of rolls that can be removed

  Solution (❛ ֊ ❛)

How to Run

Each day has its own solution file and input file. To run a solution:

node day_X/solution.js