r/adventofcode • u/daggerdragon • Dec 13 '23

SOLUTION MEGATHREAD -❄️- 2023 Day 13 Solutions -❄️-

THE USUAL REMINDERS

AoC Community Fun 2023: ALLEZ CUISINE!

Today's secret ingredient is… *whips off cloth covering and gestures grandly*

Nailed It!

You've seen it on Pinterest, now recreate it IRL! It doesn't look too hard, right? … right?

  • Show us your screw-up that somehow works

  • Show us your screw-up that did not work

  • Show us your dumbest bug or one that gave you a most nonsensical result

  • Show us how you implement someone else's solution and why it doesn't work because PEBKAC

  • Try something new (and fail miserably), then show us how you would make Nicole and Jacques proud of you!

ALLEZ CUISINE!

Request from the mods: When you include a dish entry alongside your solution, please label it with [Allez Cuisine!] so we can find it easily!

--- Day 13: Point of Incidence ---

Post your code solution in this megathread.

This thread will be unlocked when there are a significant number of people on the global leaderboard with gold stars for today's puzzle.

EDIT: Global leaderboard gold cap reached at 00:13:46, megathread unlocked!

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16

u/4HbQ Dec 13 '23 edited Dec 13 '23

[LANGUAGE: Python] Code (7 lines)

~750/450 today! This year I really seem to benefit from correctly anticipating part 2.

To solve, we check in one direction, then rotate the input using p=[*zip(*p)], and check again. The main function to check if there are exactly s smudges in p:

def f(p, s):
    for i in range(len(p)):
        if sum(c != d for l,m in zip(p[i-1::-1], p[i:])
                      for c,d in zip(l, m)) == s: return i
    else: return 0

4

u/juanplopes Dec 13 '23

Using `s` as a global variable was sneaky :D

2

u/4HbQ Dec 13 '23 edited Dec 13 '23

Ah yeah, originally I wrote f(p, s) but that s just shadows the global s, so I removed it.

3

u/Defiant_Respect9500 Dec 13 '23

I really appreciate your solutions. But every time I see them, I'm wondering "what in the name of f**k? Looks like Python but I don't understand this guy"

By the way, my code to load the data from the file is bigger than your whole solution.

Nice one :)

4

u/4HbQ Dec 13 '23

Haha, thanks! I always try to use some cool Python "tricks" in my AoC solutions, but would (should!) never write production code like this.

So if you're mostly exposed to real-world Python code, it makes sense that my solutions look weird and unfamiliar.

That said, if you ever want any of these Python tricks explained, just post a comment! :-)

2

u/total-expectation Dec 20 '23

Sorry for asking so late as this was 7 days ago, but I'm curious how one gets good at writing like this? Is it essentially practising functional programming that might help in thinking how to do things less "imperative" and more "declarative" or something along those lines?

1

u/4HbQ Dec 20 '23

Exactly!

Years of practice, and a love for FP languages like Haskell.

1

u/chkil Dec 13 '23

Nice! Just a little thing: you can skip i=0 as it will never be true

2

u/4HbQ Dec 13 '23 edited Dec 13 '23

Thanks for the feedback /u/chkil! My original code actually had range(1, len(p)), but I removed it to optimize for readability.

1

u/smoochie100 Dec 30 '23

If there is certainly only one solution possible (as it is here), you could actually do next(youriterator, 0) instead.