input: Write a function to find the k-th largest element in an array.
  assert getKthLargest([3, 2, 1, 5, 6, 4], 2) == 5
  assert getKthLargest([3, 2, 3, 1, 2, 4, 5, 5, 6], 4) == 4
  assert getKthLargest([1, 2, 3, 4, 5], 1) == 5
output: def getKthLargest(arr, k):
      arr.sort(reverse=True)
      return arr[k-1]