/**

 * Definition for singly-linked list.

 * struct ListNode {

 *     int val;

 *     struct ListNode *next;

 * };

 */

struct ListNode* removeElements(struct ListNode* head, int val) {

    struct ListNode* s = (struct ListNode* )malloc(sizeof(struct ListNode));

    s->next = head;

    struct ListNode* pre = s;

    struct ListNode* cur = head;

    while (cur)

    {

        if (cur->val == val)

        {

            pre->next = cur->next;

        }

        else

        {

            pre = cur;

        }

        cur = cur->next;

    }

    return s->next;

}