声明一个简单的computer类，有数据成员芯片(cpu)、内存(ram)、光驱(cdrom)等等，有两个公有成员函数run、stop。cpu为CPU类的一个对象，ram为RAM类的一个对象，cdrom为CDROM类的一个对象，声明并实现这个类。-Declare a simple computer class, the data members of the chips (CPU), memory (ram), CD-ROM drive (cdrom), two public member function run, stop. cpu is an object like the CPU, ram RAM like an object, cdrom CDROM like an object, declare and implement this class.