[LeetCode]Delete Node in a Linked List

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］只知道当前节点，要删除当前节点。和通常的删除不同的是，我们不知道前一个节点。

我们可以利用当前节点与前一个节点的联系，把后一个节点拷贝过来。然后删除后一个节点，相当于实现了删除操作。

/**
* 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 == nullptr)
return;
ListNode *next = node->next;
node->val = node->next->val;
node->next = next->next;
delete next;
}
};