https://leetcode.com/problems/remove-linked-list-elements/description/

RemoveListElements.java

class RemoveListElements {
    public static void main(String[] args) {
        ListNode node6_2 = new ListNode(6);
        ListNode node5 = new ListNode(5, node6_2);
        ListNode node4 = new ListNode(4, node5);
        ListNode node3 = new ListNode(3, node4);
        ListNode node6_1 = new ListNode(6, node3);
        ListNode node2 = new ListNode(2, node6_1);
        ListNode node1 = new ListNode(1, node2);
        printNodes(new RemoveListElements().removeElements(node1, 6));
    }

    public ListNode removeElements(ListNode head, int val) {
        ListNode result = null;
        ListNode finalResult = null;
        while(head!=null){
            if(head.val!=val){
                if(result==null){
                    result = new ListNode(head.val);
                    finalResult = result;
                }else{
                    ListNode ln = new ListNode(head.val);
                    result.next = ln;
                    result = result.next;
                }
            }
            head = head.next;
        }
        return finalResult;
    }

    static void printNodes(ListNode result){
        if (result!=null){
            while(result!=null){
                System.out.print(result.val+" ");
                result = result.next;
            }
        }else{
            System.out.println("result is null");
        }
    }
}

class ListNode {
     int val;
     ListNode next;
     ListNode() {}
     ListNode(int val) { this.val = val; }
     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
}