定义一个有理数类，实现有理数的加减乘除运算 程序要求定义并实现一个有理数类，通过重载运算符+、-、*、/对所有有理数进行算数运算；写一个优化函数，使有理数约去公分母。 -Define a rational number class, achieve rational numbers, Math computation process requires the definition and implementation of a rational number class, by ove

有理数的四则运算，没有用到数据结构的知识，不过基本功能已经实现。-Rational numbers of arithmetic, there is no knowledge of data structures used, but the basic function has been achieved.