DeleteDuplicates82

[underwindfall]

• https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii/

• 思路

  • 哨兵

• [x] 刷15mins

• [x] 刷5mins

//time O(n)
    //space O(1)
    public ListNode deleteDuplicates(ListNode head) {
        ListNode dummy = new ListNode();
        ListNode prev = dummy;
        ListNode curr = head;
        dummy.next = curr;
        while (curr != null) {
            if (curr.next != null && curr.next.val == curr.val) {
                while (curr.next != null && curr.next.val == curr.val) {
                    curr = curr.next;
                }
                prev.next = curr.next;
            } else {
                prev = curr;
            }
            curr = curr.next;
        }
        return dummy.next;
    }