Remove Duplicates from Sorted Array II

Question:

Follow up for "Remove Duplicates":
What if duplicates are allowed at most twice?

For example,
Given sorted array nums = [1,1,1,2,2,3],

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3. It doesn't matter what you leave beyond the new length.

Solution:

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
            int n=nums.size();
    if(n<=2) return n;
    int i=2;
    for(int j=2;j<n;j++)
    {
        if(nums[j]!=nums[i-2])
        {
            nums[i]=nums[j];
            i++;

        }
    }
    return i;
        
    }
};