实现“向量”的运算符重载 （3维数）

向量的维数可自定义，实现的运算有以下：相加、 相减、点积、自增、自减

以上运算不只能是现在向量与向量之间的运算，同时也可以与常数的运算。-Achieve the " vector"　operator overloading (three dimensional) vector dimension can be customized to achieve the operation are the following: addition, subtraction, dot product, since the increase, since by the above operation is now not only vector and vector of between the computing, but also with constant computing.