题目

删除链表中等于给定值val的所有节点。

样例

给出链表 1->2->3->3->4->5->3, 和 val = 3, 你需要返回删除3之后的链表:1->2->4->5

解题

加入头结点进行删除

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    /**
     * @param head a ListNode
     * @param val an integer
     * @return a ListNode
     */
    public ListNode removeElements(ListNode head, int val) {
        // Write your code here
        if(head == null)
            return head;
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        head = dummy;
        
        while (head.next != null) {
            if (head.next.val == val) {
                head.next = head.next.next;
            } else {
                head = head.next;
            }
        }
        
        return dummy.next;
        
    }
}