Remove Linked List Elements.md

Hint

Create a ListNode dummy, where dummy.next = head. This will make it easier to remove elements at the head of the list, if necessary.

Provided Code

class ListNode {
    int val;
    ListNode next;
    ListNode(int x) {
        val = x;
    }
}

Solution

class Solution {
    public ListNode removeElements(ListNode head, int val) {
        ListNode dummy = new ListNode(-1);
        dummy.next = head;
        ListNode n = dummy;
        while (n.next != null) {
            if (n.next.val == val) {
                n.next = n.next.next;
            } else {
                n = n.next;
            }
        }        
        return dummy.next;
    }
}

Time/Space Complexity

• Time Complexity: O(n)
• Space Complexity: O(1)

Links

• github.com/RodneyShag