46 lines
1.2 KiB
Python
46 lines
1.2 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
|
||
|
|
import itertools
|
||
|
|
import sys
|
||
|
|
from copy import deepcopy
|
||
|
|
from typing import Iterator, List, Tuple
|
||
|
|
|
||
|
|
Grid = List[List[str]]
|
||
|
|
|
||
|
|
|
||
|
|
def update(grid: Grid) -> Grid:
|
||
|
|
def neightbours(x: int, y: int) -> Iterator[Tuple[int, int]]:
|
||
|
|
for dx, dy in itertools.product(range(-1, 2), range(-1, 2)):
|
||
|
|
if dx == 0 and dy == 0:
|
||
|
|
continue
|
||
|
|
|
||
|
|
new_x, new_y = x + dx, y + dy
|
||
|
|
if 0 <= new_x < len(grid) and 0 <= new_y < len(grid[0]):
|
||
|
|
yield new_x, new_y
|
||
|
|
|
||
|
|
new_grid = deepcopy(grid)
|
||
|
|
|
||
|
|
for x, y in itertools.product(range(len(grid)), range(len(grid[0]))):
|
||
|
|
num_alive = sum(grid[nx][ny] == "#" for nx, ny in neightbours(x, y))
|
||
|
|
if num_alive == 0 and grid[x][y] == "L":
|
||
|
|
new_grid[x][y] = "#"
|
||
|
|
elif num_alive >= 4 and grid[x][y] == "#":
|
||
|
|
new_grid[x][y] = "L"
|
||
|
|
|
||
|
|
return new_grid
|
||
|
|
|
||
|
|
|
||
|
|
def solve(grid: Grid) -> int:
|
||
|
|
while (new_grid := update(grid)) != grid:
|
||
|
|
grid = new_grid
|
||
|
|
return sum(sum(pos == "#" for pos in line) for line in grid)
|
||
|
|
|
||
|
|
|
||
|
|
def main() -> None:
|
||
|
|
input = [line.strip() for line in sys.stdin.readlines()]
|
||
|
|
print(solve([[line[i] for i in range(len(line))] for line in input]))
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|