Adevent of Code 2024 Day 14

from pathlib import Path
import re
from collections import Counter

TEST = """**REDACTED**"""


def parse(input: str) -> list[tuple[int, int, int, int]]:
    robots: list[tuple[int, int, int, int]] = []
    for row in input.splitlines():
        pos = [int(n) for n in re.findall("-?\\d+", row)]
        assert len(pos) == 4
        robots.append(tuple(pos))
    return robots


def part1(input: str, width: int = 101, height: int = 103, moves: int = 100) -> int:
    quadrants: list[int] = [0, 0, 0, 0]
    w2, h2 = width // 2, height // 2
    for robot in parse(input):
        px, py, vx, vy = robot
        fx = (px + moves * vx) % width
        fy = (py + moves * vy) % height
        if fx != w2 and fy != h2:
            quadrants[(1 if fx > w2 else 0) + (2 if fy > h2 else 0)] += 1
    return quadrants[0] * quadrants[1] * quadrants[2] * quadrants[3]


assert part1(TEST, 11, 7) == 12

INPUT = Path("input/day14.txt").read_text()
part1_total = part1(INPUT)
print(f"{part1_total=:,}")  # 230,900,224


def treeness(
    move: int,
    robots: list[tuple[int, int, int, int]],
    width: int,
    height: int,
    branches=6,
) -> int:
    # Tree picture will have a lot of robots with close neighbours
    points = {
        complex((px + move * vx) % width, (py + move * vy) % height)
        for px, py, vx, vy in robots
    }
    neighbours = sum(
        len(
            {
                p + 1,
                p - 1,
                p + 1j,
                p - 1j,
                p + 1 + 1j,
                p + 1 - 1j,
                p - 1 + 1j,
                p - 1 - 1j,
            }
            & points
        )
        for p in points
    )
    return neighbours


def show(
    move: int, robots: list[tuple[int, int, int, int]], width: int, height: int
) -> None:
    grid = [[" "] * width for i in range(height)]
    for px, py, vx, vy in robots:
        fx = (px + move * vx) % width
        fy = (py + move * vy) % height
        grid[fy][fx] = "*"
    for row in grid:
        print("".join(row))


def part2(inp: str, width: int = 101, height: int = 103, moves: int = 100) -> int:
    w2, h2 = width // 2, height // 2
    robots = parse(inp)
    moves: Counter[int] = Counter()
    for move in range(1, width * height):
        moves[move] = treeness(move, robots, width, height)

    for move, score in moves.most_common(1):
        print(move, score)
        show(move, robots, width, height)

    return moves.most_common(1)[0][0]


print(f"{part2(INPUT)=:,}") # 6532