Advent of Code 2024 day 22 part 2

from collections import deque, Counter
from argparse import ArgumentParser, FileType


def parse(src):
    return [int(line) for line in src.splitlines() if line != '']


def mix_prune(secret, other):
    return (secret ^ other) & 0xFFFFFF


def step(secret):
    secret = mix_prune(secret, secret << 6)
    secret = mix_prune(secret, secret >> 5)
    return mix_prune(secret, secret << 11)


def score_sequences(number):
    current_sequence = deque([], maxlen=4)
    scores = Counter()

    for n in range(2000):
        if n >= 4:
            sequence = tuple(current_sequence)
            if sequence not in scores:  # only count the first appearance
                scores[tuple(current_sequence)] = number % 10

        new_number = step(number)
        current_sequence.append((new_number % 10) - (number % 10))
        number = new_number

    return scores


def main(numbers, verbose):
    total_scores = Counter()
    for number in numbers:
        total_scores += score_sequences(number)
        if verbose:
            best_seq, result = total_scores.most_common(1)[0]
            print(f'current best: {best_seq}, {result}')

    if not verbose:
        result = total_scores.most_common(1)[0][1]
    return result


arg_parser = ArgumentParser()
arg_parser.add_argument('src', type=FileType('r'))
arg_parser.add_argument('-v', '--verbose', action='store_true')

if __name__ == '__main__':
    args = arg_parser.parse_args()
    print(main(parse(args.src.read()), args.verbose))