Given an integer array `arr`, return the length of a maximum size turbulent subarray of `arr`.

A subarray is turbulent if the comparison sign flips between each adjacent pair of elements in the subarray.

More formally, a subarray `[arr[i], arr[i + 1], ..., arr[j]]` of `arr` is said to be turbulent if and only if:

- For `i <= k < j`:
  - `arr[k] > arr[k + 1]` when `k` is odd, and
  - `arr[k] < arr[k + 1]` when `k` is even.
- Or, for `i <= k < j`:
  - `arr[k] > arr[k + 1]` when `k` is even, and
  - `arr[k] < arr[k + 1]` when `k` is odd.

Example 1:

    Input: arr = [9,4,2,10,7,8,8,1,9]
    Output: 5
    Explanation: arr[1] > arr[2] < arr[3] > arr[4] < arr[5]

Example 2:

    Input: arr = [4,8,12,16]
    Output: 2

Example 3:

    Input: arr = [100]
    Output: 1

Constraints:

- `1 <= arr.length <= 4 * 104`
- `0 <= arr[i] <= 109`