from typing import Generator
from collections.abc import Iterable
from collections import Counter

Bits = tuple[bool, ...]
Input = list[Bits]

def column(rows: Iterable[Bits], n: int) -> Generator[bool, None, None]:
    for row in rows:
        yield row[n]

def most_common(bits: Iterable[bool]) -> bool:
    freqs: list[tuple[bool, int]] = Counter(bits).most_common()
    if freqs[0][1] == freqs[1][1]:
        return True
    return freqs[0][0]

def bits_to_int(bits: Bits) -> int:
    ret: int = 0
    for i, b in enumerate(reversed(bits)):
        if b:
            ret += 2 ** i
    return ret

def part1(nums: Input) -> int:
    nbits: int = len(nums[0])
    gamma: Bits = tuple(most_common(column(inp, i)) for i in range(nbits))
    epsilon: Bits = tuple(not bit for bit in gamma)
    return bits_to_int(gamma) * bits_to_int(epsilon)

def part2_impl(nums: Input, complement: bool, bit: int = 0) -> Bits:
    if len(nums) == 1:
        return nums[0]
    target: bool = most_common(column(nums, bit))
    if complement:
        target = not target
    nums = list(filter(lambda n: n[bit] == target, nums))
    return part2_impl(nums, complement, bit + 1)

def part2(nums: Input) -> int:
    oxygen: Bits = part2_impl(nums, False)
    co2: Bits = part2_impl(nums, True)
    return bits_to_int(oxygen) * bits_to_int(co2)

inp: Input = [tuple(bool(int(c)) for c in l.strip()) for l in open('3.in')]

print(part1(inp))
print(part2(inp))