用运算符重载设计有理分数类，实现+、-、*、/等操作。

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创建一个有理分数类Rational，有两个数据成员，一个构造函数，四个运算符重载函数，一个显示函数和一个约简函数。其中数据成员有分子numerator和分母denominator，构造函数可以避免分母为0，对不是约化型的分数进行约化。显示函数显示计算结果。约简函数对分数进行化简-Design a rational fraction class with operator overloading and achieve+,-,*,/operations. Tip: create a rational fraction of the Rational class has two data members, a constructor, the four operator overloading function and a display function and a reduction function. Which data members numerator and denominator of molecular denominator, constructor to avoid the denominator is 0, not about of scores reduced. The display function displays the calculated results. Reduction function scores simplification