simple and easy understand solution
if it\'s help, please up \u2B06 vote! \u2764\uFE0F\n\n# Code\n\nclass Solution {\npublic:\n    ListNode* mergeInBetween(ListNode* list1, int a, int b, ListNode*
# if it\'s help, please up \u2B06 vote! \u2764\uFE0F\n\n# Code\n```\nclass Solution {\npublic:\n    ListNode* mergeInBetween(ListNode* list1, int a, int b, ListNode* list2) \n    {\n        ListNode* tmp = list1, *tmp2 = list2;\n        while(b--) tmp = tmp->next;\n        while(tmp2->next) tmp2 = tmp2->next;\n        tmp2->next = tmp->next;\n\n        a--;\n        tmp = list1;\n        while(a--) tmp = tmp->next;\n\n        tmp->next = list2;\n        return list1;\n    }\n};\n```
['Linked List', 'C', 'C++', 'Java', 'TypeScript', 'Rust', 'Ruby', 'Kotlin', 'JavaScript', 'C#']