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].

思路：依然是双指针遍历

代码：

int removeDuplicates(int A[], int n) {
        if(n <= 2)
return n;
int res=1;
int i=0;
int j=1;
while(j < n)
{
if(A[i] == A[j])
{
if(j == i+1)
{
A[res++]=A[j];
}
++j;
}
else
{
   A[res++]=A[j];
i=j;
++j;
}
}
return res;
    }