237. 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.

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/**
* 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)
{
node->val=node->next->val;
node->next=node->next->next;
}
};

这题因为指明不会是尾结点，所以我就没对node的后继节点进行是否为空的判断了。这题的主题思想就是并不是直接删除node，而是将node的后继节点的值赋给node节点（值被保存，为后面删除做铺垫），这就说明node的值被覆盖了，这时再删除node的后继节点值，因为会重复，或者说不重要了可删除，就将node的后继指针跨过node->next，而是指向node->next->next，自然node->next就被从单链表上删掉了