对外经济贸易大学《C++程序设计》课件-lecture1Introduction.pptVIP

CS 1031Introduction(Outline)The Software Development ProcessPerformance Analysis: the Big Oh.Abstract Data Types Introduction to Data Structures对外经济贸易大学《C++程序设计》 CS 1032The Software Development Process CS 1033Software Development Requirement analysis, leading to a specification of the problemDesign of a solutionImplementation of the solution (coding)Analysis of the solutionTesting, debugging and integrationMaintenance and evolution of the system. CS 1034Specification of a problem A precise statement/description of the problem. It involves describing the input, the expected output, and the relationship between the input and output. This is often done through preconditions and postconditions. CS 1035Design Formulation of a method, that is, of a sequence of steps, to solve the problem. The design “language” can be pseudo-code, flowcharts, natural language, any combinations of those, etc. A design so expressed is called an algorithm(s). A good design approach is a top-down design where the problem is decomposed into smaller, simpler pieces, where each piece is designed into a module. CS 1036Implementation Development of actual C++ code that will carry out the design and solve the problem. The design and implementation of data structures, abstract data types, and classes, are often a major part of design implementation. CS 1037Implementation(Good Principles)Code Re-useRe-use of other people’s softwareWrite your software in a way that makes it (re)usable by othersHiding of implementation details: emphasis on the interface. Hiding is also called data encapsulationData structures are a prime instance of data encapsulation and code re-use CS 1038Analysis of the Solution Estimation of how much time and memory an algorithm takes. The purpose is twofold: to get a ballpark figure of the speed and memory requirements to see if they meet the targetto compare competing designs and thus choose the best before any further investment in the application (implementation, testing, et