中文摘要：

通过对现有超长整数四则运算的算法的综合比较，提出一套相对完善的算法的设计目标。基于字符数组提出一套无符号超长整数四则运算算法，给出了加减乘除4个算法的逻辑思路和程序代码，精确实现了超长整数的四则运算，并将算法应用于科学研究的实践当中。

英文摘要：

The design objective of a set of relatively perfect algorithms is proposed by comprehensively comparing the several algorithms of very long integer arithmetic, and a set of unsigned very long integer arithmetic algorithms based on character array is introduced. There are logic plans and programming source codes of the four arithmetic operations （addition, subtraction, multiplication and division） among the algorithms are given. The exact results of very long integer arithmetic can be obtained by using the set of algorithms, which have been applied to a calculation task in a scientific research work.