203. Remove Linked List Elements

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

删除链表中跟val相同的节点

C++(32ms):

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        ListNode* preHead = new ListNode(0) ;
        preHead->next = head ;
        ListNode* cur = preHead ;
        while(cur){
            if (cur->next && cur->next->val == val)
                cur->next = cur->next->next ;
            else
                cur = cur->next ;
        }
        return preHead->next ;
    }
};