1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     struct ListNode *next;
 6  * };
 7  */
 8 
 9 /*思路:先建立一個帶頭結點的空連結串列,然後先插入第一個元素,然後再比較舊連結串列和新連結串列的元素值,不同再插入,
10 也可以把不同的值都放入一個數組，然後再根據陣列建表
11 */
12 struct ListNode* deleteDuplicates(struct ListNode* head){
13
 
     struct ListNode * h1 = (struct ListNode * )malloc(sizeof(struct ListNode)),*tail;
14     h1->next = NULL;
15     tail = h1;
16     int count = 0;
17     while(head)
18     {
19        //if(head->val != head->next->val)這句到了最後一個節點就會出錯
20         if(count==0)
21         {
22              struct
 
 ListNode * h2 = (struct ListNode * )malloc(sizeof(struct ListNode));
23              h2->val = head->val;
24              h2->next = NULL;
25              tail->next = h2;
26              tail = h2;
27             count++;
28         }else{
29             if(tail->val!=head->val){
 
30                 struct ListNode * h2 = (struct ListNode * )malloc(sizeof(struct ListNode));
31              h2->val = head->val;
32              h2->next = NULL;
33              tail->next = h2;
34              tail = h2;
35             }
36         }
37          head = head->next;
38     }
39 
40     return h1->next;
41 }