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python-aoc-2020/day11/part2.py
2020-12-12 13:49:48 +01:00

43 lines
1.2 KiB
Python

import numpy as np
from day11.common import char_to_int
seats = np.array([[char_to_int(x) for x in line.strip()] for line in open("input.txt")], dtype=np.byte)
RAYS = [(-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (-1, 1), (0, 1), (1, 1)]
occupied = -1
def find_neighbor(idx, ray):
idx = tuple(map(sum, zip(idx, ray)))
while 0 <= idx[0] < seats.shape[0] and 0 <= idx[1] < seats.shape[1]:
if seats[idx] == -1:
return 0
elif seats[idx] == 0:
idx = tuple(map(sum, zip(idx, ray)))
continue
else:
return 1
else:
return 0
while True:
new_occupied = np.count_nonzero(seats == 1)
if occupied == new_occupied:
break
occupied = new_occupied
result = np.zeros_like(seats)
for idx, val in np.ndenumerate(seats):
if val == 0:
continue
neighbors = sum(find_neighbor(idx, ray) for ray in RAYS)
if val == -1 and neighbors == 0:
result[idx] = 1
elif val == 1 and neighbors >= 5:
result[idx] = -1
else:
result[idx] = seats[idx]
seats = result
print(occupied)
print(occupied)