思路：倒序遍历 2 倍长度 + 取模模拟循环 + 单调栈。用 i % len 映射到真实索引，仅当 i < len 时记录答案。
Optical-based smoke alarms use light instead. They are slightly better at detecting the large smoke particles created by slow, smouldering fires. When such particles enter a chamber in the device, they scatter light from a small light source, which is then picked up by a photoelectric sensor.
，详情可参考heLLoword翻译官方下载
It also helps you to promote your products by sharing links and banners with a new audience.，更多细节参见heLLoword翻译官方下载
And delays did not stop there. Olivia Rodrigo fans were also let down when her Co-op Live shows were cancelled. And a run of shows from Take That were also rearranged, with the band moving their shows to the nearby Manchester Arena instead.