Advent of code 2021 day 21

def process2(s, part2=False):
  lines = s.strip('\n').split('\n')
  pos0, pos1 = int(lines[0][27:]) - 1, int(lines[1][27:]) - 1
  die_sum_distribution = collections.Counter(
      sum(die) for die in itertools.product([1, 2, 3], repeat=3))

  @functools.lru_cache(maxsize=None)
  def compute(pos0, pos1, score0, score1):
    wins0 = wins1 = 0
    for total, count in die_sum_distribution.items():
      new_pos0 = (pos0 + total) % 10
      new_score0 = score0 + (new_pos0 + 1)
      if new_score0 >= 21:
        wins0 += count
      else:
        d_wins1, d_wins0 = compute(pos1, new_pos0, score1, new_score0)
        wins0 += d_wins0 * count
        wins1 += d_wins1 * count
    return wins0, wins1

  return max(*compute(pos0, pos1, 0, 0))