1 /** 2  * Definition for singly-linked list. 3  * struct ListNode { 4  *     int val; 5  *     ListNode *next; 6  *     ListNode(int x) : val(x), next(NULL) {} 7  * }; 8  */ 9 class Solution {10 public:11     /**12      * @param head a ListNode13      * @param val an integer14      * @return a ListNode15      */16     ListNode *removeElements(ListNode *head, int val) {17         // Write your code here18         // Find the first non-Val node19         while ( head != NULL && head->val == val ) {20             head = head->next;21         }22         // If the head is NULL, return23         if ( head == NULL ) {24             return head;25         }26         // Remove the left val nodes27         ListNode *pre = head;28         ListNode *cur = pre->next;29         while ( cur != NULL ) {30             if ( cur->val != val ) {31                 pre->next = cur;32                 pre = pre->next;33             }34             cur = cur->next;35         }36         // In case of the tail has val node37         pre->next = cur;38         // return39         return head;40     }41 };