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 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.

class Solution
{
public:
int removeDuplicates(vector<int>& nums)
{
int len = nums.size();
if(len == 0)
return 0;
int lastIndex = 0;
int cnt = 0;
for(int i=0; i<len;)
{
while(i < len && nums[i] == nums[lastIndex])
{
cnt++;
i++;
}
while(cnt > 2)
{
nums[lastIndex++] = -1000000;
cnt--;
}
lastIndex = i;
cnt = 0;
}
vector<int> tmp;
for(int i=0; i<len; i++)
if(nums[i] != -1000000)
tmp.push_back(nums[i]);
nums = tmp;

return nums.size();
}
};