Implementation of Unlimited Integer

This paper analyses the expression of digital symbol and calculation of number system, and develops 2n based number system whose digital symbol can be easily expressed with built-in data type variable in high-level programming language. By researching the characteristic of scalable queue templates in visual C++ template library, it gives the implementation scheme of unlimited integer class based on automatic scalable queue. In this scheme, one unlimited integer is made up by one queue, each element of the queue is one digital of the number. This paper also researches the algorithm of arithmetic calculations and tests its performance in RSA cryptogram of 1024 or more bits. The result indicates that this numeric class is practicable, and it can be a member of base library of high level programming language.