zlacker

i feel like using the log operator for avoiding a loop is also cheating as well because under the hood there is likely to be a loop. i would have expected the non-looping solution to use either recursion or some abuse of itertools which is really just using a loop as well.

  import itertools
  def digitLength(n):
    if n == 0:
      return 1
    *_, last = itertools.takewhile(lambda acc: acc[0] != 0, itertools.accumulate(itertools.repeat(None), lambda acc, x: (acc[0]//10, acc[1] + 1), initial=(n, 0)))
    return last[1]

the problem is interesting in python because i think the looping solution is not optimal because it performs N divisions for an arbitrarily large integer whereas I think there should be a solution that performs O(log(N)) multiplications for an arbitrarily large integer. in other languages with fixed integers its not really an issue how many operations you do since its effectively constant.