Remove Linked List Elements

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

Example:

Input:  1->2->6->3->4->5->6, val = 6
Output: 1->2->3->4->5

这题比较简单，有一点要记住的是，如果删除当前节点，那么当前节点就不需要next了。

/**
 * 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) {
        if(head == NULL)return NULL;

        ListNode *p = new ListNode(0), *q;
        p->next = head;
        q = p;
        while(p && p->next)
        {
            if(p->next && p->next->val == val)
            {
                p->next = p->next->next;
            }
            else
                p = p->next;
        }
        return q->next;
    }
};