题目：

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.

题目大意：

编写一个函数来删除单链表中的节点（尾部除外），只允许访问该节点。
假设链表是1 -> 2 -> 3 -> 4和你被赋予第三个节点的值3，链表应该1 -> 2 -> 4在调用你的函数后。

解题思路

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    void deleteNode(ListNode* node) {
        if (node->next == NULL)
        {
            return ;
        }
        node->val = node->next->val;
        node->next = node->next->next;
    }
};