input: def randomized_list(num_list):
      """Randomizes a list of given integers using the optimized Fisher-Yates algorithm.
      >>> randomized_list([1, 2, 3, 4, 5])
      [2, 5, 1, 4, 3]
      >>> randomized_list([10, 20, 30, 40, 50])
      [50, 40, 20, 10, 30]
      """
output:     import random
      for i in range(len(num_list) - 1, 0, -1):
          j = random.randint(0, i)
          num_list[i], num_list[j] = num_list[j], num_list[i]
      return num_list