mirror of
https://github.com/thib8956/advent-of-code.git
synced 2024-12-26 13:56:29 +00:00
59 lines
1.8 KiB
Python
59 lines
1.8 KiB
Python
#!/usr/bin/env python3
|
|
from collections import defaultdict
|
|
|
|
|
|
def part1(infile):
|
|
memory = defaultdict(int)
|
|
for line in infile:
|
|
left, right = line.split("=")
|
|
if left.startswith("mask"):
|
|
one_mask = right.translate(right.maketrans("X", "0"))
|
|
zero_mask = right.translate(right.maketrans("X10", "001"))
|
|
else:
|
|
address = int(left.split("[")[1].rstrip("] ")) # mem[42] -> 42
|
|
value = int(right.rstrip())
|
|
memory[address] = value & ~int(zero_mask, 2) | int(one_mask, 2)
|
|
|
|
return sum(memory.values())
|
|
|
|
|
|
def part2(infile):
|
|
memory = defaultdict(int)
|
|
for line in infile:
|
|
left, right = line.split(" = ")
|
|
if left.startswith("mask"):
|
|
mask = right.rstrip()
|
|
else:
|
|
value = right.rstrip()
|
|
address = apply_mask(left.split("[")[1].rstrip("] "), mask)
|
|
for addr in generate_floating_addresses(address):
|
|
memory[int(addr, 2)] = int(value)
|
|
return sum(memory.values())
|
|
|
|
|
|
def apply_mask(address, mask):
|
|
address = bin(int(address)).lstrip("0b")
|
|
address = address.zfill(36)
|
|
for index, bit in enumerate(mask):
|
|
if bit == "1":
|
|
address = address[:index] + "1" + address[index + 1 :]
|
|
elif bit == "X":
|
|
address = address[:index] + "X" + address[index + 1 :]
|
|
return address
|
|
|
|
|
|
def generate_floating_addresses(address):
|
|
index = address.find("X")
|
|
if index == -1:
|
|
return [address]
|
|
a1 = generate_floating_addresses(address[:index] + "0" + address[index + 1 :])
|
|
a2 = generate_floating_addresses(address[:index] + "1" + address[index + 1 :])
|
|
return a1 + a2
|
|
|
|
|
|
if __name__ == "__main__":
|
|
with open("input.txt") as infile:
|
|
print(part1(infile))
|
|
infile.seek(0)
|
|
print(part2(infile))
|