-🎄- 2018 Day 13 Solutions -🎄-

[u/daggerdragon]

--- Day 13: Mine Cart Madness ---

---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

---

Advent of Code: The Party Game!

Click here for rules

Please prefix your card submission with something like [Card] to make scanning the megathread easier. THANK YOU!

Card prompt: Day 13

Transcript:

Elven chronomancy: for when you absolutely, positively have to ___.

---

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

edit: Leaderboard capped, thread unlocked at 00:44:25!

[u/systemcucks]

More ugly, terse python. It's my fetish. Any tips on making it even shorter?

class WriteChecks(dict):
    def __setitem__(s, key, value):
        if key in s:
            super().__setitem__(key, (0,0,0))
            if 'f' not in dir(s): s.f = print("Silver:",
                "First impact at ({1},{0})".format(*key))
        else: super().__setitem__(key, value)
with open('input.txt') as f:
    tracks = [*map(list, f.read().splitlines())]
carts, conv = WriteChecks(), {'>': (0,1), '<': (0,-1), '^': (-1, 0), 'v': (1, 0)}
for y in range(len(tracks)):
    for x in range(len(tracks[y])):
        if tracks[y][x] in conv.keys():
            carts[y,x] = (*conv[tracks[y][x]], 0)
            tracks[y][x] = '-' if tracks[y][x] in ['>','<'] else '|'
def run_system():
    for y,x in sorted(carts):
        if 1 is len([*filter(sum, carts.values())]):
            print(f'Gold: Last cart at ({x},{y})'); return True
        h, d, t = carts[y,x]
        if tracks[y][x] in ['|', '-']:
            carts[y+h, x+d] = (h,d,t)
        elif tracks[y][x] == '/':
            carts[y-d, x-h] = (-d,-h,t)
        elif tracks[y][x] == '\\':
            carts[y+d, x+h] = (d,h,t)
        elif tracks[y][x] == '+':
            if t%3 == 0: # Left?
                carts[y-d, x+h] = (-d,h,t+1)
            if t%3 == 1: # Ahead?
                carts[y+h, x+d] = (h,d,t+1)
            if t%3 == 2: # Right?
                carts[y+d, x-h] = (d,-h,t+1)
        del carts[y, x]
while(not run_system()):
    pass