Remove Duplicates from Sorted Array II -- leetcode

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].

加入一个计数器，用于统计重复字符的个数。

class Solution {
public:
    int removeDuplicates(int A[], int n) {
        if (!n) return 0;
        int count = 1;
        int idx = 0;
        for (int i=1; i<n; i++) {
            if (A[idx] == A[i]) {
                ++count;
                if (count <= 2)
                    A[++idx] = A[i];
            }
            else {
                A[++idx] = A[i];
                count = 1;
            }
        }

        return idx+1;
    }
};