aoc2021/day16.py

113 lines
3.5 KiB
Python

from math import prod
from tools.aoc import AOCDay
from typing import Any, List
def get_packet(bit_rep: str) -> (str, int): # packet, packet_length
msg_type = int(bit_rep[3:6], 2)
index = 6
if msg_type == 4:
while bit_rep[index] == "1":
index += 5
index += 5
else:
op_type = bit_rep[index]
index += 1
if op_type == "0":
sub_pkg_len = int(bit_rep[index:index+15], 2)
index += 15 + sub_pkg_len
else:
sub_pkg_count = int(bit_rep[index:index+11], 2)
index += 11
for x in range(sub_pkg_count):
_, sub_pkg_len = get_packet(bit_rep[index:])
index += sub_pkg_len
return bit_rep[:index], index
def get_subpackages(packet: str) -> List[str]:
ptype = int(packet[3:6], 2)
if ptype == 4:
return [packet]
else:
plist = []
op_type = packet[6]
if op_type == "0":
sub_pkg_len = int(packet[7:22], 2)
sub_packages = packet[22:22+sub_pkg_len]
while "1" in sub_packages:
sub_packet, sub_pkg_len = get_packet(sub_packages)
sub_packages = sub_packages[sub_pkg_len:]
plist.append(sub_packet)
else:
sub_pkg_count = int(packet[7:18], 2)
index = 18
for x in range(sub_pkg_count):
sub_packet, sub_pkg_len = get_packet(packet[index:])
index += sub_pkg_len
plist.append(sub_packet)
return plist
def get_versions(packet: str) -> int:
version = int(packet[0:3], 2)
ptype = int(packet[3:6], 2)
if ptype == 4:
return version
else:
for p in get_subpackages(packet):
version += get_versions(p)
return version
def get_value(packet: str) -> int:
while "1" in packet:
this_packet, pkg_len = get_packet(packet)
pkg_type = int(this_packet[3:6], 2)
packet = packet[pkg_len:]
if pkg_type == 0:
return sum(get_value(p) for p in get_subpackages(this_packet))
elif pkg_type == 1:
return prod(get_value(p) for p in get_subpackages(this_packet))
elif pkg_type == 2:
return min(get_value(p) for p in get_subpackages(this_packet))
elif pkg_type == 3:
return max(get_value(p) for p in get_subpackages(this_packet))
elif pkg_type == 4:
index = 6
value = 0
while this_packet[index] == "1":
value = value * 16 + int(this_packet[index + 1:index + 5], 2)
index += 5
value = value * 16 + int(this_packet[index + 1:index + 5], 2)
return value
elif pkg_type == 5:
sub_pkg = get_subpackages(this_packet)
return get_value(sub_pkg[0]) > get_value(sub_pkg[1])
elif pkg_type == 6:
sub_pkg = get_subpackages(this_packet)
return get_value(sub_pkg[0]) < get_value(sub_pkg[1])
elif pkg_type == 7:
sub_pkg = get_subpackages(this_packet)
return get_value(sub_pkg[0]) == get_value(sub_pkg[1])
class Day(AOCDay):
test_solutions_p1 = [16, 12, 23, 31, 1007]
test_solutions_p2 = [3, 54, 7, 9, 1, 0, 0, 1, 834151779165]
def getBits(self) -> str:
bits = bin(int(self.getInput(), 16))[2:]
return "0" * (len(self.getInput()) * 4 - len(bits)) + bits
def part1(self) -> Any:
return get_versions(self.getBits())
def part2(self) -> Any:
return get_value(self.getBits())