237. Delete Node in a Linked List*

237. Delete Node in a Linked List*

https://leetcode.com/problems/delete-node-in-a-linked-list/

题目描述

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

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.

C++ 实现 1

这也是一道让人印象深刻的题, 和 206. Reverse Linked List* 一样. 这道题比较特别的地方在于, 它不直接删除指定的节点 node 本身, 而是将 next 节点的值替换 node 节点的值, 然后再删除 next 节点. 一般我们做链表的题, 通常是不允许通过修改节点值的操作来达到目的. 注意删除 next 节点前需要将 next 节点后面的节点接在 node 节点后.

class Solution {
public:
    void deleteNode(ListNode* node) {
        auto tmp = node->next;
        node->val = tmp->val;
        node->next = tmp->next;
        delete tmp;
    }
};