AoC2020-Day24pt1

day24pt1.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)
}

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

    def add(self, coord):
        d_x, d_y = coord
        x, y = self.point
        self.point = (x + d_x, y + d_y)

    def flip(self):
        self.white = not self.white
        self.flip_cnt += 1

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


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()
    print(f'flipped {tile}')


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)

        for key in all_tiles:
            print(all_tiles[key])
        print('\n')
        for key in all_tiles:
            if all_tiles[key].flip_cnt == 1:
                print(all_tiles[key])
        print('\n')
        for key in all_tiles:
            if all_tiles[key].flip_cnt > 1:
                print(all_tiles[key])

        print(sum([1 for key in all_tiles if not all_tiles[key].white]))



if __name__ == '__main__':
    day24()