Remove Duplicates from Sorted Array II

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

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

Your function should return length = 5, and A is now [1,1,2,2,3].

class Solution {
public:
    int removeDuplicates(int A[], int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int last = INT_MAX, counter = 0;
        int pre = 0, i = 0;
        int new_length = n;
        for(i = 0; i < new_length; i ++){
            if (A[i] != last){
                if (counter > 2){
                    for(int j = i; j < n; j++){
                        A[j - counter + 2] = A[j];
                    }
                    new_length -= (counter - 2);
                    i -= (counter - 2);
                }
                counter = 1; 
                last = A[i];
            }else{
                counter++;
            }    
        }
        if (counter > 2){
            for(int j = i; j < n; j++){
                A[j - counter + 2] = A[j];
            }
            new_length -= (counter - 2);        
        }
        return new_length;
    }
};