/**
knakul853
**/

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {

        if(nums.empty()) return 0;
        int n = (int)nums.size();

        int l = 0;

        for( int i = 1; i < n; i++ )
        {
            if(nums[l] !=  nums[i])
            {
                nums[++l] = nums[i];
            }
        }

        return l+1;
    }
};