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.
从链表中，删除指定的节点，但又没有给出前指针，所以先交换当前节点和下一节点的值，然后删除下一节点即可。代码如下：
class Solution {
public:
void deleteNode(ListNode* node) {
if(!node||!node->next) return ;
node->val=node->next->val;
node->next=node->next->next;
}
};