advent-of-code/2023/3/two.py
2024-12-25 12:59:49 +01:00

43 lines
1.1 KiB
Python

#!/usr/bin/env python3
import sys
input_file = sys.argv[1]
with open(input_file) as fd:
lines = [line.rstrip() for line in fd.readlines()]
height = len(lines)
width = len(lines[0])
gears = dict()
sum = 0
for i in range(height):
line = lines[i]
pn_str = ""
for j in range(width):
c = line[j]
# print(19, c)
if c.isnumeric():
if not pn_str:
left = j
pn_str += c
# print(20, c, pn_str)
if pn_str and (j == width - 1 or not line[j + 1].isnumeric()):
for ii in range(max(i - 1, 0), min(i + 1, height - 1) + 1):
for jj in range(max(left - 1, 0), min(j + 1, width - 1) + 1):
cc = lines[ii][jj]
# print(ii, jj, cc)
if cc == "*":
gears.setdefault((ii, jj), list())
gears[(ii, jj)].append(int(pn_str))
pn_str = ""
for gear_numbers in gears.values():
if len(gear_numbers) != 2:
continue
gear_ratio = gear_numbers[0] * gear_numbers[1]
sum += gear_ratio
print(sum)