m0978.py

"""Longest Turbulent Subarray
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 * 10^4
* 0 <= arr[i] <= 10^9
"""