链表//移除链表元素

删除链表中等于给定值 val 的所有节点。

示例:

输入: 1->2->6->3->4->5->6, val = 6
输出: 1->2->3->4->5

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode removeElements(ListNode head, int val) {
        ListNode cur = new ListNode(-1);
        ListNode p = cur;
        while(head != null){
            if(head.val == val){
                cur.next = head.next;
            }else{
                cur.next = head;
                cur = cur.next;
            }
            head = head.next;
        }
        return p.next;
    }
}

/**
 * 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 FirstNode(0);
        FirstNode.next = head;
        ListNode *p = &FirstNode;
        while(p != NULL){
            ListNode *tmp = p->next;
            if(tmp != NULL&&tmp->val == val)
            {
                p->next = tmp->next;
                delete tmp;
            }else
                p = p->next;
        }
        return FirstNode.next;
    }
};