一个程序，确定由4个并联的子电路组成的电路的总电阻。子电路由两个串联或并联的电阻器组成。由键盘输入，向屏幕输出结果。写一个电路的基类和两个派生类（分别处理串联和并联），使用虚基类（抽象基类）和多态。对所有的子电路使用一个循环计算总的电阻。-A procedure, make sure the child by four parallel circuit circuit of total resistance. A sub circuit consists of two series or parallel resistors. From the keyboard, the screen output. Write a circuit of the superclass and two derived class (series and parallel processing) respectively, using virtual superclass (abstract base classes) and polymorphism. For all the sub circuit loop computations using a total resistance.