[Leetcode] 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：

1. 前提是整个链表是有序的

2. 循环遍历整个链表，对于相同的元素值要注意将前指针指向后续的下一个结点

直接上Code:

/*** Definition for singly-linked list.* struct ListNode {*     int val;*     struct ListNode *next;* };*/
struct ListNode* deleteDuplicates(struct ListNode* head) {if (head == NULL)return NULL;struct ListNode* p = NULL, *q = NULL;p = head;q = p->next;while(q)	{struct ListNode *tmp = q->next;if (!(p->val ^ q->val)){//same elementp->next = tmp;free(q);	q = tmp;}else		{p = q;q = q->next;}}return head;
}

算法时间复杂度O(n)。