Day 3: Mull It Over
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
You are viewing a single thread.
View all comments 
2 points
*
Python
After a bunch of fiddling yesterday and today I finally managed to arrive at a regex-only solution for part 2. That re.DOTALL is crucial here.
import re
from pathlib import Path
def parse_input_one(input: str) -> list[tuple[int]]:
p = re.compile(r"mul\((\d{1,3}),(\d{1,3})\)")
return [(int(m[0]), int(m[1])) for m in p.findall(input)]
def parse_input_two(input: str) -> list[tuple[int]]:
p = re.compile(r"don't\(\).*?do\(\)|mul\((\d{1,3}),(\d{1,3})\)", re.DOTALL)
return [(int(m[0]), int(m[1])) for m in p.findall(input) if m[0] and m[1]]
def part_one(input: str) -> int:
pairs = parse_input_one(input)
return sum(map(lambda v: v[0] * v[1], pairs))
def part_two(input: str) -> int:
pairs = parse_input_two(input)
return sum(map(lambda v: v[0] * v[1], pairs))
if __name__ == "__main__":
input = Path("input").read_text("utf-8")
print(part_one(input))
print(part_two(input))
