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) {        ListNode* cur;        while(head && head->val==val){            cur = head;            head = head->next;            free(cur);        }        cur = head;        if(head==NULL)            return head;        while(cur->next!=NULL){            if(cur->next->val == val){                ListNode * temp = cur->next;                cur -> next = temp->next;                free(temp);            }            else{                cur = cur ->next;            }        }        return head;    }};