class Solution:
  def reverseVowels(self, s: str) -> str:
    # TODO: Write your code here
    vowels_arr = ['a', 'e', 'u', 'o', 'i']
    # front and back pointers
    # travel until they are both vowel then swap
    f_ptr, b_ptr = 0, len(s) - 1
    str_list = list(s)
    while f_ptr < b_ptr:
      while str_list[f_ptr].lower() not in vowels_arr and f_ptr < b_ptr:
        f_ptr += 1
      while str_list[b_ptr].lower() not in vowels_arr and b_ptr > f_ptr:
        b_ptr -= 1
      str_list[f_ptr], str_list[b_ptr] = str_list[b_ptr], str_list[f_ptr]
      f_ptr += 1
      b_ptr -= 1
    return "".join(str_list)