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
/**
* 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 head;
ListNode *tmp = head;
while(head && head->val == val){ head = head->next; delete tmp; tmp = head; }
if(head==NULL) return head;
ListNode *p = head, *q = head->next;
while(q){
tmp = q;
q = q->next;
if(tmp->val == val){ delete tmp; p->next = q; }
else p = tmp;
}
return head;
}
};