摘要： Table6.1.Selected Numeric TypesTypeDescriptionDoubleDouble-precision floating point. A common choice for floating-point data.FloatSingle-precision floating point. Often used when interfacing with C.IntFixed-precision signed integer; minimum range [-2^29..2^29-1]. Commonly used.Int88-bit signed integ 阅读全文

摘要： 求一个数的因子的数量。X=a^n*b^m*c^p will have (n + 1)(m + 1)(p + 1) factors.//abc都是质因子28=2^2*7 will have 3*2 = 6 factors 因为：28的质因子是 2 2 7；28的所有因子必是由这些质因子构成；构造这些因子时：2可以取 0 、1、 2 个。7可以取0 、1 个；所以28因子的数量是：3×2=6 。http://mathforum.org/library/drmath/view/55843.htmlhttp://www.cnblogs.com/zhouyinhui/archive/2011/ 阅读全文