AOC2022_Day17

tower = []
highest = 0

shapes = list(patterns.keys())
wind_pattern_count = len(line)

iteration_count = 0
cache = {}
rock_height_cache = {}
break_outer_loop = False
rocks_to_drop = 1000000000000
for rock_number in tqdm(range(rocks_to_drop)):
    to_add = 10 - (len(tower) - highest)
    for k in range(to_add):
        tower.append([0 for i in range(7)])

    rock = shapes[rock_number % 5]
    rock_pattern = patterns[rock]
    left_edge = left_edges[rock]
    right_edge = right_edges[rock]
    bottom_edge = bottom_edges[rock]

    rock_y = highest + 3
    rock_x = 2
    rock_height = len(rock_pattern)
    rock_width = len(rock_pattern[0])
    start_wind = iteration_count % wind_pattern_count
    while True:
        end_wind = iteration_count % wind_pattern_count
        wind_pattern = line[end_wind]
        wind_pattern = 1 if wind_pattern == '>' else -1
        iteration_count += 1

        is_safe = True
        if wind_pattern == 1:
            if rock_x + rock_width > 6:
                is_safe = False
            else:
                is_safe = not any(tower[rock_y + p][rock_x + x_offset] == 1 for p, x_offset in enumerate(right_edge))
        else:

            if rock_x - 1 < 0:
                is_safe = False
            else:
                is_safe = not any(tower[rock_y + p][rock_x + x_offset] == 1 for p, x_offset in enumerate(left_edge))

        if is_safe:
            rock_x += wind_pattern

        is_settled = False
        if rock_y == 0:
            is_settled = True
        else:
            is_settled = any(tower[rock_y + y_offset][rock_x + p] == 1 for p, y_offset in enumerate(bottom_edge))

        if is_settled:
            for i in range(rock_height):
                for j in range(rock_width):
                    if rock_pattern[i][j] == 1:
                        tower[i+rock_y][j+rock_x] = rock_pattern[i][j]
            highest = max(highest, rock_y + rock_height)
            if highest == rock_height + rock_y:
                if (rock, start_wind, end_wind) in cache:
                    if (rock, start_wind, end_wind) in cache:
                        cache_value = cache[(rock, start_wind, end_wind)]
                        if len(cache_value) > 1:
                            # stable loop
                            if cache_value[-1] - cache_value[-2] == rock_number - cache_value[-1]:
                                break_outer_loop = True
                                break
                cache[(rock, start_wind, end_wind)] = cache.get((rock, start_wind, end_wind), [])
                cache[(rock, start_wind, end_wind)].append(rock_number)
                rock_height_cache[rock_number] = highest
            break
        else:
            rock_y -= 1
    if break_outer_loop:
        break

if break_outer_loop:
    rocks_fallen = rock_number - earlier_rock_number
    height_of_loop = highest - rock_height_cache[earlier_rock_number]
    remaining = (rocks_to_drop - rock_number) % rocks_fallen
    highest = highest + ((rocks_to_drop - rock_number) // rocks_fallen) * height_of_loop + rock_height_cache[remaining + earlier_rock_number] - rock_height_cache[earlier_rock_number] - 1

print(highest)