Remove Duplicates from Sorted Array II 题解

题目来源：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].

解题思路：

    int removeDuplicates(int A[], int n)
    {
        if(n <= 2) return n;
        int index = 0;
        int i = 0;
        while(i < n)
        {
            int count = 1;
            while (i+1 < n && A[i+1] == A[i])
            {
                count++; i++;
            }
            if (count >= 2)
            {
                A[index++] = A[i]; //A[i+1] != A[i]
                A[index++] = A[i++];
            } else
                A[index++] = A[i++];
        }
        return index;
    }