input: Write a function to shuffle an array using Fisher-Yates algorithm.
  assert sorted(shuffleArray([1, 2, 3, 4]))==[1,2,3,4]
  assert sorted(shuffleArray(['A', 'B', 'C', 'D']))==['A','B','C','D']
  assert sorted(shuffleArray([10, 20, 30, 40, 50]))==[10,20,30,40,50]
output: import random
  
  def shuffleArray(arr):
      n = len(arr)
      for i in range(n-1, 0, -1):
          j = random.randint(0, i)
          arr[i], arr[j] = arr[j], arr[i]
      return arr