day24pt2.py

from typing import List

all_tiles = dict()
vector_map = {
    'ne': (1, 1),
    'nw': (-1, 1),
    'e': (2, 0),
    'w': (-2, 0),
    'sw': (-1, -1),
    'se': (1, -1)
}


def add_coords(coord, vect):
    d_x, d_y = vect
    x, y = coord
    return x + d_x, y + d_y


class Tile:
    def __init__(self, point=(0, 0)):
        self.point = point
        self.white = True
        self.should_flip = False

    def add(self, vect):
        self.point = add_coords(vect, self.point)

    def flip(self, force=False):
        if self.should_flip or force:
            self.white = not self.white
            self.should_flip = False

    def adj_black_count(self):
        cnt = 0
        for direction in vector_map:
            vect = vector_map[direction]
            key = add_coords(self.point, vect)
            if all_tiles.get(key) is None:
                t = Tile(point=key)
                all_tiles[key] = t
            if not all_tiles[key].white:
                cnt += 1
        return cnt

    def decide(self):
        if self.white and self.adj_black_count() == 2:
            self.should_flip = True
        elif not self.white and (self.adj_black_count() == 0 or self.adj_black_count() > 2):
            self.should_flip = True

    def __repr__(self):
        return f'{hex(id(self))} white: {self.white} coord: {self.point}'


def parse_dir_tokens(line: str) -> List[str]:
    tokens = []
    idx = 0
    while idx < len(line):
        ch = line[idx]
        if idx <= len(line) - 2:
            ch2 = line[idx + 1]
            if ch == 's':
                if ch2 == 'w':
                    tokens.append('sw')
                    idx += 1
                elif ch2 == 'e':
                    tokens.append('se')
                    idx += 1
            elif ch == 'n':
                if ch2 == 'w':
                    tokens.append('nw')
                    idx += 1
                elif ch2 == 'e':
                    tokens.append('ne')
                    idx += 1
            else:
                tokens.append(ch)
        else:
            tokens.append(ch)
        idx += 1
    return tokens


def flip_tile(instrs: List[str]):
    tile = Tile()
    for ist in instrs:
        tile.add(vector_map[ist])

    if all_tiles.get(tile.point) is None:
        all_tiles[tile.point] = tile
        print(f'added {tile}')
    else:
        tile = all_tiles[tile.point]
        print(f'reused {tile}')
    tile.flip(True)
    print(f'flipped {tile}')


def flip(coord):
    if all_tiles.get(coord) is None:
        all_tiles[coord] = Tile(point=coord)
    all_tiles[coord].flip()


def day24():
    with open('day24input.txt', 'r') as f:
        for line in f.readlines():
            tokens = parse_dir_tokens(line.strip('\n'))
            print(tokens)
            flip_tile(tokens)
        print(sum([1 for key in all_tiles if not all_tiles[key].white]))

        for i in range(1, 101):
            for coord in [c for c in all_tiles]:
                tile = all_tiles[coord]
                tile.decide()
                if not tile.white:
                    for direction in vector_map:
                        vect = vector_map[direction]
                        moved_coord = add_coords(coord, vect)
                        all_tiles[moved_coord].decide()
            for coord in all_tiles:
                tile = all_tiles[coord]
                tile.flip()
            print(f'day {i} black cnt: {sum([1 for key in all_tiles if not all_tiles[key].white])}')


if __name__ == '__main__':
    day24()