class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if(nums.size()==0) return 0;
        int len = 0;
        for(size_t i=0; i<nums.size()-1; i++)
        {
            if(nums[i] < nums[i+1]) 
            {
                nums[len] = nums[i];
                len++;
            }
             
        }
        nums[len] = nums.back();
        len++;
        return len;
        
    }
};