Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.

题目意思：

　　写一个函数删除单链表中的某个结点，函数只给出了删除的结点

解题思路：

　　只需要将删除的结点与其下一个结点交换值即可，同时调整好链表指针

源代码：

 class Solution {

 public:

     void deleteNode(ListNode* node) {

         if( node->next == NULL){

             delete node;

             node = NULL;

         }

         swap(node->val, node->next->val);

         ListNode* nextNode = node->next;

         node->next = nextNode->next;

         delete nextNode;

     }

 };