aoc2024day14.py

# === Parsing ===
import re

LINE_RE = re.compile(r"p=(\d+),(\d+) v=(-?\d+),(-?\d+)")
WIDTH = 101
HEIGHT = 103

robots = []
with open("input.txt", "r") as f:
    for line in f:
        px, py, vx, vy = map(int, LINE_RE.match(line).groups())
        robots.append(((px, py), (vx, vy)))

print(robots[0])


# === Part 1 ===
from collections import Counter
from math import prod


def move(pos, velocity, steps):
    px, py = pos
    vx, vy = velocity

    return (
        (px + steps * vx) % WIDTH,
        (py + steps * vy) % HEIGHT,
    )


final_robots = [move(pos, vel, 100) for pos, vel in robots]

print(
    prod(
        Counter(
            (px < WIDTH / 2, py < HEIGHT / 2)  # Encode the quadrant.
            for px, py in final_robots
            if px != WIDTH // 2 and py != HEIGHT // 2
        ).values()
    )
)


# === Part 2 ===
from PIL import Image


def print_robots(robots):
    for y in range(HEIGHT):
        for x in range(WIDTH):
            if (x, y) in robots:
                print("#", end="")
            else:
                print(" ", end="")
        print()


def make_frame(robots):
    image = Image.new("L", (WIDTH, HEIGHT), "black")
    pixels = image.load()

    for x, y in robots:
        pixels[x, y] = 255

    return image


for steps in range(7056):
    moved_robots = {move(pos, vel, steps) for pos, vel in robots}
    frame = make_frame(moved_robots)
    # frame.save(f"frames/frame{steps:04}.png")

print(7055)