83. 删除排序連結清單中的重複元素(Java遞歸實作)

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if (head == null || head.next == null) return head;

        head.next = deleteDuplicates(head.next);

        return head.val == head.next.val ? head.next : head;
    }
}