0978-longest-turbulent-subarray.adoc

978. Longest Turbulent Subarray

{leetcode}/problems/longest-turbulent-subarray/[LeetCode - Longest Turbulent Subarray^]

A subarray A[i], A[i+1], …​, A[j] of A is said to be turbulent if and only if:

• For i ⇐ k < j, A[k] > A[k+1] when k is odd, and A[k] < A[k+1] when k is even;

• OR, for 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

Note:

• 1 ⇐ A.length ⇐ 40000

• 0 ⇐ A[i] ⇐ 10^9

link:{sourcedir}/_0978_LongestTurbulentSubarray.java[role=include]