Question：

Follow up for "Remove Duplicates":

What if duplicates are allowed at most twice?

For example,

Given sorted array nums = [1,1,1,2,2,3],

Your function should return length = 5, with the first five elements of nums being 1, 1, 2, 2 and 3.
It doesn‘t matter what you leave beyond the new length.

允许重复2次，删除重复超过3次的元素，返回删除后的长度。

Algorithm：

见程序

Accepted Code：

class Solution {
public:
    int removeDuplicates(vector<int>& nums) {
        if(nums.size()<=2)return nums.size();
        vector<int>::iterator it=nums.begin();
        for(;it!=nums.end();)
        {
            int temp=*it;
            int j=0;
            while(*it==temp)
            {
                if(it==nums.end())
                    break;
                j++;
                if(j>2)
                    nums.erase(it);
                else
                    it++;
            }
        }
        return nums.size();
    }
};