Advent of code 2023 day 12

def day12(s0, *, part2=False, speedup=True):

  @functools.cache
  def compute(s, counts):
    if not s:
      return 0 if counts else 1
    if speedup and len(s) < len(counts) + sum(counts):
      return 0
    sum_matches = compute(s[1:], counts) if s[0] in '.?' else 0
    if counts:
      n = counts[0]
      if s[:n].replace('?', '#') == '#' * n and s[n] in '.?':
        sum_matches += compute(s[n + 1 :], counts[1:])
    return sum_matches

  total = 0
  for line in s0.splitlines():
    s, right = line.split()
    counts = tuple(map(int, right.split(',')))
    if part2:
      s = '?'.join([s] * 5)
      counts *= 5
    total += compute(s + '.', counts)

  return total