DSA problem
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 between each pair of adjacent elements in the subarray flips. 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 arr[k] > arr[k+1] when k is even, and arr[k] < arr[k+1] when k is odd.
In short, the comparison signs must strictly alternate between < and > along the subarray.
Examples
Example 1
Input:
arr = [9,4,2,10,7,8,8,1,9]Output:
5Explanation: arr[1] > arr[2] < arr[3] > arr[4] < arr[5] is the turbulent subarray [4,2,10,7,8] of length 5.
Example 2
Input:
arr = [4,8,12,16]Output:
2Explanation: The signs never alternate (all increasing), so the longest turbulent subarray is any adjacent pair, length 2.
Example 3
Input:
arr = [100]Output:
1Explanation: A single element is trivially turbulent with length 1.
Constraints
- 1 <= arr.length <= 4 * 10^4
- 0 <= arr[i] <= 10^9
3 hints and a full solution walkthrough with step-by-step visualizations are available in the practice editor.