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.

Given linked list -- head = [4,5,1,9], which looks like following:

Example 1:

Input: head = [4,5,1,9], node = 5
Output: [4,1,9]
Explanation: You are given the second node with value 5, the linked list should become 4 -> 1 -> 9 after calling your function.

Example 2:

Input: head = [4,5,1,9], node = 1
Output: [4,5,9]
Explanation: You are given the third node with value 1, the linked list should become 4 -> 5 -> 9 after calling your function.

Note:

• The linked list will have at least two elements.
• All of the nodes' values will be unique.
• The given node will not be the tail and it will always be a valid node of the linked list.
• Do not return anything from your function.

思路

没有给链表的起点，只给了一个要删除的node。

将node的下一个节点值赋给当前节点，然后删除下一个节点即可。

c++11

/**
 * 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;
        ListNode* tmp = node->next;
        node->next = tmp->next;
        delete tmp;
    }
};

ac结果：

Runtime: 16 ms, faster than 60.64% of C++ online submissions for Delete Node in a Linked List.
Memory Usage: 9.1 MB, less than 70.43% of C++ online submissions for Delete Node in a Linked List.