978. Longest Turbulent Subarray

Medium

30 Points

Array

Dynamic Programming

Sliding Window

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:

Examples

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