978. 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 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.

class Solution {
public:
    int maxTurbulenceSize(vector<int>& arr) {
        int res = 1, n = arr.size();
        for(int i = 0, ma1 = 1, ma2 = 1; i < n - 1; i++) {
            if(i & 1) {
                if(arr[i] > arr[i + 1]) ma1 += 1;
                else ma1 = 1;
                
                if(arr[i] < arr[i + 1]) ma2 += 1;
                else ma2 = 1;
            } else {
                if(arr[i] < arr[i + 1]) ma1 += 1;
                else ma1 = 1;
                
                if(arr[i] > arr[i + 1]) ma2 += 1;
                else ma2 = 1;
            }
            res = max({res, ma1, ma2});
        }

        return res;
    }
};