LeetCode:Remove Linked List Elements

Problem:

Remove all elements from a linked list of integers that have value val;

Example

Given :1->2->6->3->4->5->6 val=6

Return:1->2->3->4->5Solution:

 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* removeElements(ListNode* head, int val) {
12         
13         if(head==NULL) return NULL;
14         ListNode dummy(-1);
15         ListNode *p=&dummy;
16         p->next=head;
17         ListNode *newhead=p;
18         
19         while(p!=NULL)
20         {  
21             if(p->next!=NULL)
22             {
23             if(p->next->val==val)
24             {
25                 ListNode *temp=p->next;
26                 p->next=temp->next;
27                 delete temp;
28                 
29                 if(p->next!=NULL&&p->next->val!=val)
30                     p=p->next;
31                 else
32                     continue;
33             }
34             else
35                 p=p->next;
36            
37             }
38             else
39                 break;
40         }
43         return newhead->next;
44     }
45 };

 

posted @ 2016-01-18 21:52  尾巴草  阅读(130)  评论(0)  编辑  收藏  举报