class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if(nums.empty()) return 0;
        int i = 0;
        for(int j = 0; j < nums.size(); j++){
            if(nums[i] != nums[j]){
                i++;
                nums[i] = nums[j];
            }
        }

        return i + 1;
    }
};