题解 | #删除有序链表中重复的元素-I#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
struct ListNode* deleteDuplicates(struct ListNode* head)
{
	if (head == NULL || head->next == NULL)
		return head;
	//同样采取多指针的方式来使用记录和删除元素
	struct ListNode* cur = head;
	struct ListNode* next = cur->next;
	struct ListNode* nextnext = next->next;
	//定义三个指针，方便记录删除和重新链接
	while (next)
	{
		if (cur->val != next->val)
		{
			cur = next;
			next = next->next;
			if (nextnext)
				nextnext = nextnext->next;
		}
		else
		{
			cur->next = nextnext;
			free(next);
			next = nextnext;
			if (nextnext)
				nextnext = nextnext->next;
		}
	}
	return head;
}