【11_83】Remove Duplicates from Sorted List

这道题本质上不难，难的是细节处理，容易出错。

第一遍写的代码越改越大，越臃肿，此时，不如推倒重写，果然，第二次一遍过。

Remove Duplicates from Sorted List

My Submissions

Question

Total Accepted: 90731 Total Submissions: 255705 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.

下面是Discuss里面的好代码：只有三行！！！

Java写法

 public ListNode deleteDuplicates(ListNode head) {
         if(head == null || head.next == null)return head;
         head.next = deleteDuplicates(head.next);
         return head.val == head.next.val ? head.next : head;
 }

另一个好代码，和我的思想差不多，不过更简洁：

 public class Solution {
     public ListNode deleteDuplicates(ListNode head) {
         if (head == null) return head;

         ListNode cur = head;
         while(cur.next != null) {
             if (cur.val == cur.next.val) {
                 cur.next = cur.next.next;
             }
             else cur = cur.next;
         }
         return head;
     }
 }

 然后是我自己写的：

C语言

 /**
  * Definition for singly-linked list.
  * struct ListNode {
  *     int val;
  *     struct ListNode *next;
  * };
  */
 struct ListNode* deleteDuplicates(struct ListNode* head) {
     if (head == NULL)
         return NULL;
     if (head->next == NULL)
         return head;

     struct ListNode* p = head;
     struct ListNode* q = p->next;
     while(p->next != NULL)  {
         if(p->val == p->next->val)  {
             p->next = p->next->next;
         }
         else if(p->next != NULL)
             p = p->next;
     }

     return head;
 }