Python 3 | Dummy Node O(N) Time Solution
\nclass Solution:\n    def mergeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:\n        d=ListNode(0)\n        t=0\n        r=ListNode(0,d)\n     
```\nclass Solution:\n    def mergeNodes(self, head: Optional[ListNode]) -> Optional[ListNode]:\n        d=ListNode(0)\n        t=0\n        r=ListNode(0,d)\n        while head:\n            if head.val!=0:\n                t+=head.val\n            else:\n                print(t)\n                if t!=0:\n                    d.next=ListNode(t)\n                    d=d.next\n                    t=0\n            head=head.next\n        return r.next.next\n```
['Linked List', 'Python', 'Python3']