input: Write a function to randomize a list of given integers using an optimized Fisher-Yates algorithm. The function should return the randomized list. If the input list is empty, the function should return an empty list.
  assert randomized_list([1, 2, 3, 4, 5])==[3, 2, 5, 1, 4] # Example output
  assert randomized_list([10, 20, 30])==[30, 10, 20] # Example output
  assert randomized_list([])==[]
output: def randomized_list(lst):
      import random
      for i in range(len(lst) - 1, 0, -1):
          j = random.randint(0, i)
          lst[i], lst[j] = lst[j], lst[i]
      return lst