#978
Longest Turbulent Subarray
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array · dynamic programming · sliding window
Description
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 is even.
- Or, for i <= k < j:
- arr[k] > arr[k + 1] when k is even, and
- arr[k] < arr[k + 1] when k is odd.
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
Solution