Leetcode40: 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

/** * 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 *cur = head, *next = head->next;         while (next != NULL) {             if (next->val == val) {                 cur->next = next->next;                 delete next;                 next = cur->next;             } else {                 cur = cur->next;                 next = next->next;             }         }         if (head->val == val) {             cur = head;             head = head->next;             delete cur;         }         return head;    }};