Easy Solution || Beginners Friendly
Code\n\nclass Solution {\npublic:\n    ListNode* mergeNodes(ListNode* head) {\n        ListNode *temp = head, *temp2 = head->next;\n        int sum = 0;\n      
# Code\n```\nclass Solution {\npublic:\n    ListNode* mergeNodes(ListNode* head) {\n        ListNode *temp = head, *temp2 = head->next;\n        int sum = 0;\n        while(temp2){\n            if(temp2->val == 0){\n                temp->next = new ListNode(sum);\n                temp->next->next = temp2->next;\n                temp = temp->next; \n                sum = 0; \n            }\n            sum+= temp2->val;\n            temp2 = temp2->next;\n        }\n        return head->next;\n    }\n};\n```
['C++']