说明：  Duck 公司在仓库安装了红外报警装置，如图所示，所有红外线互不相交。n 个发射器和 n 个接收器将平面分成 n + 1 个区域，从左到右分别记作 0、1、…、n。现在技术人员正在进行调试，对于每个点，需要快速知道它处于哪个区域。若正好处于红外线上，则视为处于右边的区域。
(Duck company has installed infrared alarm device in the warehouse, as shown in the figure, all infrared rays do not intersect each other. N transmitters and N receivers divide the plane into N + 1 regions, and record them as 0, 1, and n. Now technicians are debugging, and for each point, you need to quickly know which area it is in. If it is on the infrared, it is considered to be in the right area.)