[Leetcode]83. Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

 

思路：递归比较当前节点和下一个节点的值，如果相同，返回下一节点，否则返回当前节点；

 

/**
 * 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;
    }
}