leetcode_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
         if(n<2) return n;
        int value,count =1;
        value = A[0];
        int length = 0;
        for(int i = 1;i<n;i++)
        {
           if(A[i] == value){
                count++;
                if(count >2)
                   length++;
                 else if(length >0)
                    A[i-length] = A[i];                  
           }else{
           
                value = A[i];
                count = 1;
                if(length >0)
                  A[i-length] = A[i];    
           }
        }
        return n-length ;
    }
};