链表问题

链表逆置

node *reverse(node *head)
{
	node *p1, *p2, *p3;
	p1=head, p2=p1->next;
	if(head==null || head->next==null)
		return head;

	while(p2)
	{
		p3=p2->next;
		p2->next=p1;
		p1=p2;
		p2=p3;
	}

	head->next=null;
	head=p1;
	return head;

}