**The idea is that, to remove consecutive duplicate items starting from 2 indexes away till the furthest, and thus we only need to scan the vector only once. Then return the size of vector left.**

```
class Solution {
public:
int removeDuplicates(vector<int>& nums) {
if (nums.size() <= 2) return nums.size();
for (int i = 0; i < nums.size()-2; i++)
{
int j = i + 2;
while (j < nums.size() && nums[j] == nums[i])
nums.erase(nums.begin() + j);
}
return nums.size();
}
};
```