All of the robovacs I've tested have announced out loud when they're in remote viewing mode. But not all robot vacuums provide that courtesy notification (the DJI Romo, for one, does not).
3. 递归：对左右子数组递归执行1-2步
，更多细节参见51吃瓜
领克回应「高速语音关大灯」：已完成优化方案
Москвичей предупредили о резком похолодании09:45
I’m returning the slice? Then it can’t be allocated on the stack, right?