LeetCode203：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

解法思路：在链表头添加一个结点，对链表进行遍历和删除操作。

/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */public class Solution {    public ListNode removeElements(ListNode head, int val) {        ListNode root=new ListNode(val+1);        root.next=head;        ListNode current=new ListNode(0);        current=root;        while(current.next!=null){            if(current.next.val==val)                current.next=current.next.next;            else                current=current.next;        }        return root.next;    }}