Remove Duplicates from Sorted List II

skip all the duplicate and use prev and curr and update these two.


public ListNode deleteDuplicates(ListNode head) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        if (head == null || head.next == null) return head;
       
        ListNode dummy = new ListNode(-1);
        dummy.next = head;
        ListNode prev = dummy;
        ListNode curr = head;
       
        while (curr!=null) {
            while (curr.next!=null && prev.next.val == curr.next.val) {
                curr = curr.next;
            }
           
            if (prev.next == curr) {
                prev = curr;
            } else {
                prev.next = curr.next;
            }
            curr = curr.next;
        }
        return dummy.next;

    }