Remove Linked List Elements

Leetcode

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

Tags

• Linked List

/**
 * 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 null;
        }
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        ListNode pre = dummy;
        while (head != null) {
            if (head.val == val) {
                pre.next = head.next;
            } else {
                pre = head;
            }
            head = head.next;
        }
        return dummy.next;
    }
}