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.

思路：

把下一个结点的值替换到要删除的结点。然后删除下一个结点。

代码：

/**
* 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 == NULL || node->next == NULL)
return;
ListNode *tmp = node->next;
node->val = tmp->val;
node->next = tmp->next;
delete tmp;
}
};