day_11.py

from utils import read_file


def day_11():
    row_max = col_max = 10

    def make_grid(input_data):
        grid = {}
        for row in range(row_max):
            for column in range(col_max):
                grid[(row, column)] = int(input_data[row][column])

        return grid

    def get_neighbours(coordinate):
        neighbours = []
        deltas = [(d_row, d_column) for d_row in [-1, 0, 1] for d_column in [-1, 0, 1] if not d_row == d_column == 0]
        for d_row, d_column in deltas:
            if 0 <= coordinate[0] + d_row < row_max and 0 <= coordinate[1] + d_column < col_max:
                neighbours.append((coordinate[0] + d_row, coordinate[1] + d_column))

        return neighbours

    def flash(coordinate, grid):
        if grid[coordinate] == -1:
            return 0

        grid[coordinate] += 1

        if grid[coordinate] <= 9:
            return 0
        else:
            grid[coordinate] = -1

            return 1 + sum([flash(neighbour, grid) for neighbour in get_neighbours(coordinate)])

    def process_grid(grid):
        iteration = 1
        flashes = 0

        while True:
            flashes_this_iteration = 0
            for coordinate in grid:
                flashes_this_iteration += flash(coordinate, grid)

            for coordinate in grid:
                if grid[coordinate] == -1:
                    grid[coordinate] = 0

            if iteration <= 100:
                flashes += flashes_this_iteration

            if flashes_this_iteration == row_max * col_max:
                return flashes, iteration

            else:
                iteration += 1

    return process_grid(make_grid(read_file(11)))