376. Wiggle Subsequence_medium.cpp

class Solution {
public:
//Here the main intuition is that the sequence should be 
//having alterante nuber direction 
//i.e.  greater and smaller 
//and we need to count till what lenght 
// this sequence is manintained - done usinf peaks and valleys
    int wiggleMaxLength(vector<int>& nums) {
        int size=nums.size(), peak=1, valley=1;
        for(int i=1; i<size; ++i){
                 if(nums[i]>nums[i-1]) peak = valley + 1;
            else if(nums[i]<nums[i-1]) valley = peak + 1;
        }
        return max(peak , valley );
    }
};