leetcode:83 Remove Duplicates from Sorted List－每日编程第十六题

Remove Duplicates from Sorted List

Total Accepted: 89961 Total Submissions: 253975 Difficulty: Easy

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

思路：

维持两具指针指向当前节点与相邻的下一个节点。将当前节点与下一个节点值进行比较，相等，则删除下一个节点，不等则将两个指针同时递增1步。

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode* deleteDuplicates(ListNode* head) {
12         if(head==NULL){
13             return head;
14         }
15         ListNode* p=head;
16         ListNode* q=p->next;
17         ListNode* tem;
18         while(q!=NULL){
19             if(q->val!=p->val){
20                 p=q;
21                 q=q->next;
22             }else{
23                 tem=q;
24                 q=q->next;
25                 p->next=q;
26                 delete tem;
27             }
28         }
29         return head;
30     }