int removeDuplicates(vector<int>& nums) { int size = nums.size(); int right =1,left = 0; while (right < size) { if ((nums[left] != nums[right]) && (right - left == 1)) { left++; right++; } else if (nums[left] == nums[right]) { right++; } else { nums[++left] = nums[right++]; } } return left + 1; }