978. 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