LeetCode: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.

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：本题的意思是给一个节点，从链表中中删除。常规删除一个节点是要找到它的前一个节点。本题采用的思路是把当前节点的值置为下一个节点的值，然后删除下一个节点即可O(1).

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