A subarray A[i], A[i+1], ..., A[j] of A is said to be turbulent
if and only if:
i <= k < j, A[k] > A[k+1] when k is
odd, and A[k] < A[k+1] when k is even;
i <= k < j, A[k] > A[k+1]
when k is even, and A[k] < A[k+1] when k is
odd.
That is, the subarray is turbulent if the comparison sign flips between each adjacent pair of elements in the subarray.
Return the length of a maximum size turbulent subarray of A.
Example 1:
Input: [9,4,2,10,7,8,8,1,9] Output: 5 Explanation: (A[1] > A[2] < A[3] > A[4] < A[5])
Example 2:
Input: [4,8,12,16] Output: 2
Example 3:
Input: [100] Output: 1