978

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

--------------------

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