Day 6: Trash Compactor
Megathread guidelines
- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL
FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465


Managed to keep it compact, but boy, do I hate cephalopod math >_<
Python
from csv import reader from functools import reduce from itertools import pairwise from operator import mul from pathlib import Path from typing import Any, List, Sequence def _calc(values: List[str]) -> int: match values[-1]: case "+": return sum(map(int, values[:-1])) case "*": return reduce(mul, map(int, values[:-1])) case _: return 0 def _transpose(values: Sequence[Sequence[Any]]) -> List[List[Any]]: return [[values[row][col] for row in range(len(values))] for col in range(len(values[0]))] def part_one(input: str) -> int: def _parse_input(input: str) -> List[List[str]]: return _transpose(list(map(lambda r: list(filter(None, r)), reader(input.splitlines(), delimiter=" ")))) return sum(map(_calc, _parse_input(input))) def part_two(input: str) -> int: def _parse_input(input: str) -> List[List[str]]: data = list(input.splitlines()) columns = [t[0] for t in filter(lambda t: t[1] != " ", enumerate(data[-1]))] + [len(data[0])] numbers = [[line[a:b] for line in data[:-1]] for a, b in pairwise(columns)] numbers = [list(filter(None, ["".join(num).strip() for num in column])) for column in map(_transpose, numbers)] return list(map(lambda t: t[0] + [t[1]], zip(numbers, list(filter(None, data[-1].split(" ")))))) return sum(map(_calc, _parse_input(input))) if __name__ == "__main__": input = Path("_2025/_6/input").read_text("utf-8") print(part_one(input)) print(part_two(input))