编程实现单链表反转。

struct node * reverseSingleLink(struct node * head) {
	if(head == NULL)
		return head;
	if(head->next == NULL)
		return head;
	struct node * post = head;
	struct node * cur = head->next;
	struct node * pre = cur->next;

	while(pre != NULL) {
		cur->next = post;
		post = cur;
		cur = pre;
		pre = cur->next;
	}
	cur->next = post;
	head->next = NULL;
	return cur;
}

时间复杂度： O(n)