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 --> 5

 

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         ListNode node(-1);14         node.next=head;15         ListNode *pre=&node;16         while(head!=NULL)17         {18             if(head->val==val)19             {20                 pre->next=head->next;21                 delete head;22                 head=pre->next;23             }24             else25             {26                 pre=pre->next;27                 head=head->next;28             }29 30         }31         return node.next;32     }33 };