237. Delete Node in a Linked List

Problem

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

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.

Solution

传统的解决方式需要我们知道链表的头节点，这里采用了一个巧妙的方法，将待删除的节点后的节点A赋值给它，再按常规方法删除节点A

/**
 * 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) {
        ListNode *p;
        p=node->next;
        node->val=p->val;
        node->next=p->next;
        free(p);
    }
};