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python-aoc-2020/day17/part2.py
2020-12-17 12:28:51 +01:00

26 lines
870 B
Python

#!/usr/bin/env python3
import numpy as np
from scipy import signal
DIMS = 4
lines = [[(1 if x == '#' else 0) for x in x.strip()] for x in open("input.txt")]
grid = np.array(lines, dtype=np.byte)
grid = np.expand_dims(grid, axis=tuple(range(DIMS-2)))
kernel = np.ones((3, )*DIMS, dtype=np.byte)
kernel[(1, )*DIMS] = 0
for iter in range(6):
grid = np.pad(grid, pad_width=1, mode='constant', constant_values=0)
neighbors = signal.convolve(grid, kernel, mode='same')
set_inactive = np.logical_and(grid == 1, np.floor_divide(neighbors, 2) != 1)
set_active = np.logical_and(grid == 0, neighbors == 3)
grid[set_inactive] = 0
grid[set_active] = 1
for dim in range(DIMS):
a = np.flatnonzero(grid.sum(axis=tuple(x for x in range(DIMS) if x!=dim)))
grid = grid[(slice(None), )*dim + (slice(min(a), max(a)+1), )]
print(np.sum(grid))