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

Credits:
Special thanks to @mithmatt for adding this problem and creating all test cases.

代码如下:

/**
* 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) {
if(head==null) return head;
ListNode tmp=head;

while(tmp!=null && tmp.val==val){
tmp=tmp.next;
head=head.next;
}
ListNode p=tmp;
if(tmp!=null)
tmp=tmp.next;
while(tmp!=null){
if(tmp.val==val){
p.next=tmp.next;
tmp=tmp.next;
}else{
p=p.next;
tmp=tmp.next;
}
}
return head;

}
}

运行结果：