可能很多人都曾经想过要实现一些比较大的数的阶乘，但是C++中提供的标准数据类型其存储空间太小，根本无法实现。我们可以通过其他方法来实现-many people may have thought about the need to achieve some fairly large number of factorial. But C is the standard data types storage space is too small, it is virtually impossible