struct ListNode {

     int val;

     ListNode *next;

 };

 void DeleteNode(ListNode* &pListHead, ListNode* pToBeDeleted):

     if (!pListNode || !pToBeDeleted) {

         return;

     }

     if (pToBeDeleted->next != nullptr) {//要删除的节点不是尾节点

         ListNode* pNode = pToBeDeleted->next;

         pToBeDeleted->val = pNode->val;

         pToBeDeleted->next = pNode->next;

         delete pNode;

         pNode = nullptr;

     } else if (pListHead == pToBeDeleted) {//链表只有一个节点

         delete pToBeDeleted;

         pToBeDeleted = nullptr;

         pListHead = nullptr;

     } else {//链表有多个节点，删除尾节点

         ListNode* pNode = pListHead;

         while (pNode->next != pToBeDeleted) {

             pNode = pNode->next;

         }

         pNode->next = nullptr;

         delete pToBeDeleted;

         pToBeDeleted = nullptr;

     }