input: Write a function to get the third largest distinct element in a given list of integers. If the list has fewer than three distinct elements, return None. If the list is empty, return None as well.
  
  def third_largest(lst):
      if len(lst) < 3:
          return None
      distinct = []
      for i in lst:
          if i not in distinct:
              distinct.append(i)
      distinct.sort(reverse=True)
      return distinct[2] if len(distinct) >= 3 else None
  
  assert third_largest([12, 13, 13, 45, 22, 99]) == 22
  assert third_largest([1, 2]) == None
  assert third_largest([1, 2, 3, 4, 5]) == 3
  assert third_largest([10, 20, 30, 30, 20, 10]) == 20
  assert third_largest([]) == None
output: def third_largest(lst):
      if len(lst) < 3:
          return None
      distinct = []
      for i in lst:
          if i not in distinct:
              distinct.append(i)
      distinct.sort(reverse=True)
      return distinct[2] if len(distinct) >= 3 else None