advent-of-code/2018/12/12_2.py

63 lines
1.6 KiB
Python
Executable File

#!/usr/bin/env python3
from collections import namedtuple, UserDict
Pot = namedtuple('Pot', ['id', 'plant'])
Rule = namedtuple('Rule', ['inp', 'out'])
newgen = None
class PlantDict(UserDict):
def __init__(self, cb, initialdata):
super().__init__(initialdata)
self._cb = cb
def __missing__(self, key):
val = self._cb(key)
self[key] = val
return val
def default_pot(i):
return Pot(i, False)
def parse_rule(rule):
return Rule([c == '#' for c in rule[:5]], '#' in rule.split()[-1])
def print_pots(pots):
print(''.join(['#' if pot.plant else '.' for pot in pots]))
def main():
# I’m aware that I’m overwriting a builtin here
input = []
with open('input') as f:
input = f.readlines()
new_gen = PlantDict(default_pot, enumerate([Pot(i, c == '#') for i, c in enumerate(input[0].split(': ')[1])]))
print_pots(new_gen.values())
rules = [parse_rule(r) for r in input[2:]]
before = after = 0
for i in range(1000):
before = after
old_gen = new_gen.copy()
ids = new_gen.keys()
for i in range(min(ids) - 2, max(ids) + 3):
surroundings = [p.plant for p in [old_gen[x] for x in range(i-2, i+3)]]
for rule in rules:
if surroundings == rule.inp:
new_gen[i] = Pot(i, rule.out)
break
#print_pots(new_gen.values())
after = sum([pot.id for pot in new_gen.values() if pot.plant])
diff = after - before
print(diff, before)
print(before + diff * (50000000000 - 999))
if __name__ == '__main__':
main()