基于算法框架的可重用部件设计与实现

对算法程序的功能规约进行等价变换,可以自然而且方便地得到求解问题设计思想的精确表达,即循环不变式。抽象算法又可以通过循环不变式获得。对算法程序中的算子进行提取、抽象就可以得到算法框架,而算法框架可以设计出可重用部件。文章通过对数组段极值问题的求解,展示了形式化推导不仅可以得到正确、高效的算法程序,而且具有软件重用的功能,并进一步给出了利用可重用部件求解数组段极值问题的C++实现。

Design and Implementation of Reusable Components Based on Algorithmic Frame

By transforming function specification,the loop invariant,the main ideas of solving problem,can be easily and naturally obtained.Algorithmic program also can be easily produced based on the loop invariant.Algorithmic frame can be gained by abstracting the arithmetic operators of algorithmic program.This paper discusses the effect of formal derivation in developing program and shows that the reusable components are designed with algorithmic frame The results that solve extreme value of array segment show the effect of obtaining efficient and correct algorithmic program and reusable components.Lastly,the program of solution to the extreme value of array segment is implemented with the reusable components using C++.