2018/Day11/Day11.py

51 lines
1.3 KiB
Python
Raw Permalink Normal View History

2018-12-11 14:07:24 +00:00
from sys import argv
from scipy.ndimage import uniform_filter
from scipy.signal import fftconvolve
import numpy
try:
SERIAL = int(argv[1])
except (ValueError, IndexError):
print(f"Usage: {argv[0]} [serial]")
# Build the grid.
grid = numpy.zeros((300, 300), dtype=numpy.int32)
for y, row in enumerate(grid):
rack_id = numpy.arange(1, 301, dtype=numpy.int32) + 10
power_level = (rack_id * (y + 1) + SERIAL) * rack_id
power_level = power_level // 100 % 10 - 5
grid[y] = power_level
def main(from_, to=None):
max_y, max_x = None, None
max_size = 0
max_value = 0
if to is None:
to = from_ + 1
for size in range(from_, to):
# Calculate the totals by convolving with a filter with ones.
filter_ = numpy.ones((size, size), dtype=int)
totals = fftconvolve(grid, filter_, "valid")
# Find the indices of the maximum value.
y, x = numpy.unravel_index(totals.argmax(), totals.shape)
value = totals[y, x]
if value > max_value:
max_size, max_y, max_x = size, y, x
max_value = value
if to == from_ + 1:
# If the range is one, it was part 1.
print(f"{max_x + 1},{max_y + 1}")
else:
print(f"{max_x + 1},{max_y + 1},{max_size}")
print("part 1:")
main(3)
print("part 2:")
main(1, 100)