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

Solution:

  1. /**
  2.  * Definition for singly-linked list.
  3.  * public class ListNode {
  4.  *     int val;
  5.  *     ListNode next;
  6.  *     ListNode(int x) { val = x; }
  7.  * }
  8.  */
  9. public class Solution {
  10.   public ListNode removeElements(ListNode head, int val) {
  11.     if (head == null)
  12.       return null;
  14.     ListNode f = new ListNode(0);
  15.     ListNode p = f;
  17.     while (head != null) {
  18.       if (head.val != val) {
  19.         p.next = head;
  20.         p = p.next;
  21.       }
  22.       head = head.next;
  23.     }
  25.     p.next = null;
  27.     return f.next;
  28.   }
  29. }