LeetCode - Algorithms - 203. Remove Linked List Elements

Problem

203. Remove Linked List Elements

Java

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/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode removeElements(ListNode head, int val) {
        if (head == null)
            return head;
        ListNode previousNode = head;
        if (head != null) {
            ListNode node = head.next;
            while (node != null) {
                if (node.val == val) {
                    ListNode obsoleteNode = node;
                    previousNode.next = node.next;
                    obsoleteNode = null;
                }
                else
                    previousNode = node;
                node = node.next;
            }
        }
        if (head.val == val) {
            ListNode obsoleteNode = head;
            head = head.next;
            obsoleteNode = null;
        }
        return head;
    }
}

Submission Detail

  • 65 / 65 test cases passed.
  • Runtime: 1 ms, faster than 82.56% of Java online submissions for Remove Linked List Elements.
  • Memory Usage: 40 MB, less than 10.13% of Java online submissions for Remove Linked List Elements.