monorail@DESKTOP-T7R40II:/mnt/d/Documents/advent_of_code_2020/day 1$ diff part1.py part2.py
10c10
<       for pair in itertools.combinations(entries, 2):
---
>       for group in itertools.combinations(entries, 3):

only had to change one line, and honestly only HAD to change one character

ah fuck i actually forgot to include the other lines with pair in it being changed but whatever

easy day, so of course i chose to overcomplicate it https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%202

like come on holly what the fuck is this

print(sum((is_valid(*(re.findall(r'(\d+)-(\d+) (.): (.+)', line)[0])) for line in f)))

clean it up

it just seems so WASTEFUL to have explicit loops and a temp variable so store the number of valid passwords or whatever

advent of code encourages insecure password database practices

did it first thing after waking up so it's a weird flavour of "too clever for its own good"

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%203

data validation problems are

- easy
- not fun

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%204

going to try to do day 5 as fast as possible, maybe win points

fuckin rip, not even close

rank 337 for part 1 and rank 398 for part 2

and i had to debug some shit i really should have gotten on the first go, but i don't think it would have been enough

oh well

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%205

i did a "real" pass at day 5, since my first attempt was speedrunning it to try to get on the leaderboards. i still have that code saved in a directory but i don't think that you should write code like that

that said, i still don't really get what the clever way to do part 2 would be. it feels like there should be something but honestly i have no idea

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%205

pretty embarrassed with myself for thinking for like six hours "the seat codes are related to binary, i can do something binary-esque to decode them" and then didn't realize until after implementing something that worked that it's literally just binary. F and L are 0, B and R are 1

i still used reduce(lambda x, y: x*2 + y, my_iterable) to actually convert to decimal though. i considered just replacing the characters in the string with 0s and 1s and doing int(s, 2), but i chose not to to keep the code lazy. in theory it should handle arbitrarily large airplanes without having to construct any huge strings, i think

god i'm looking at the code that i wrote as quickly as possible and for part 2 i literally do for i in range(999999):, check if i is my id, and if it is i print and break

my code that i wrote without trying to go as fast as possible is only barely nicer

surely there's a better way

bah, i'm pretty sure this code works but i typed the answer wrong into the page and now i have to wait a minute before i can type it correctly

okay now i'm on part 2 and my code actually is wrong

this works on the example set but not on my data set and i'm furious about it

def num_yes(answers):
    first, *rest = answers.split('\n')
    return sum((all((c in a for a in rest)) for c in first))

def main():
    with open('input.txt') as f:
        print(sum(map(num_yes, f.read().split('\n\n'))))

if __name__ == '__main__':
    main()

TRAILING NEWLINE

with that out of the way here's my code

easy day other than having to fight with the trailing newline for part 2

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%206

also i feel like i fairly rarely get to use first, *rest = my_iterable so that's exciting

not that it was completely necessary, i could have used answers.split('\n')[0] instead of first and answers.split('\n')[1:] instead of rest. or even just checked the answers in the first one against itself. but this is a little more clear

i feel like this code should work and i don't know why it isn't

it's giving me a reasonable answer but it's wrong, which sucks

the more i look at this code the more i convince myself that it's right, which is a shame because it's not

oh fuck me i think i figured it out

yeah i got it

part 2 was actually much easier than part 1 tbh

today was the day of off by one errors. in both parts i forgot to not count the shiny gold bag itself

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%207

day 8 was pretty easy

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%208

you can tell i like functional stuff more than the average python user because i had to write this:

def first_true(it):
    for e in it:
        if e:
            return e

i thought i could use any() for that, since it's basically just applying or over an iterable and or short circuits when it gets a truthy value, but any() returns a literal True or False while i actually needed the truthy object

everything in the iterable that function gets is a number, most of which are 0 and one of which is the solution to the problem

so i could have just used sum() but i didn't want to keep calculating when i already had the answer

okay i just tried it with sum() and the difference in execution time is completely indistinguishable so maybe it was a waste of time

catching up on aoc

day 9 solutions kinda suck but here they are. they do work i just feel like they're very naive

https://github.com/undergroundmonorail/advent-of-code-2020/tree/main/day%209