void splay(int p,int goal)
	{
		while(tr[p].fa!=goal)
		{
			int fa=tr[p].fa,grand=tr[fa].fa;
			if(grand!=goal)
			{
				if((tr[fa].son[1]==p)==(tr[grand].son[1]==fa))
				rotate(fa);
				else
				rotate(p);
			}
			else
			rotate(p);
		}
		if(!goal)
		rt=p;
		return ;
	}

还是说写假了……