有理数是一个可以转化为一个分数的数，例如2/3，533/920，-12/49都是有理数，而根号2就是无理数。在C++中，并没有预先定义有理数类型，需要时可以定义一个有理数类，将有理数的分子分母分别存放在两个整型变量中。对有理数的操作可以通过重载运算符来实现.-Is a rational number can be translated into a number of points, such as the 2/3, 533/920,-12/49 are rational, and the root 2 is irrational number. In the C++, There is no pre-defined rational type, when necessary, the definition of a rational categories, will be rational molecular denominator were stored in two integer variables. Rational operation of heavy-duty operator can be achieved.