LeetCode 82. Remove Duplicates from Sorted List II

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 2->3.

题目大意:给一个已经排序的链表,删除所有元素值出现过2次或者以上的结点,只保留元素值仅仅出现过一次的结点~

分析:p为head的next,如果p的值和head的值不同,则将head->next置为deleteDuplicates(p),返回head,否则直到找到第一个p不等于head的地方,返回deleteDuplicates(p)~