1 / 32

An Introduction to Programming with C++ Fifth Edition

Learn the problem-solving process for creating computer programs, including problem analysis, IPO charts, algorithm planning, and desk-checking. Includes the Gas Mileage Problem.

rmoser
Download Presentation

An Introduction to Programming with C++ Fifth Edition

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. An Introduction to Programming with C++Fifth Edition Chapter 2 Beginning the Problem-Solving Process

  2. Objectives • Explain the problem-solving process used to create a computer program • Analyze a problem • Complete an IPO chart • Plan an algorithm using pseudocode and flowcharts • Desk-check an algorithm An Introduction to Programming with C++, Fifth Edition

  3. Concept Lesson • Problem Solving • Solving Everyday Problems • Creating Computer Solutions to Problems • Analyzing the Problem • Planning the Algorithm • Desk-Checking the Algorithm • The Gas Mileage Problem • Summary An Introduction to Programming with C++, Fifth Edition

  4. Problem Solving • In this lesson, you will: • Explore the thought process followed when solving problems • Learn how to use a similar process to create a computer solution to a problem • Called a computer program An Introduction to Programming with C++, Fifth Edition

  5. Solving Everyday Problems • First step in solving a problem: analyze it • E.g., problem of being hungry • Next, you plan, review, implement, evaluate, and modify (if necessary) the solution • E.g., if you are still hungry An Introduction to Programming with C++, Fifth Edition

  6. Solving Everyday Problems (continued) An Introduction to Programming with C++, Fifth Edition

  7. Solving Everyday Problems (continued) An Introduction to Programming with C++, Fifth Edition

  8. Creating Computer Solutions to Problems • Analysis tools: IPO charts, pseudocode, flowcharts • To desk-check or hand-trace,use pencil, paper, and sample data to walk through algorithm • A coded algorithm is called a program An Introduction to Programming with C++, Fifth Edition

  9. Creating Computer Solutions to Problems (continued) An Introduction to Programming with C++, Fifth Edition

  10. Analyzing the Problem • Analyze a problem to: • Determine the goal of solving it • Output • Determine the items needed to achieve that goal • Input • Always search first for the output An Introduction to Programming with C++, Fifth Edition

  11. Analyzing the Problem (continued) An Introduction to Programming with C++, Fifth Edition

  12. IPO Charts • Use an IPO chart to organize and summarize the results of a problem analysis • IPO:Input, Processing, and Output An Introduction to Programming with C++, Fifth Edition

  13. IPO Charts (continued) An Introduction to Programming with C++, Fifth Edition

  14. IPO Charts (continued) An Introduction to Programming with C++, Fifth Edition

  15. Analyzing the Problem (continued) • First, reduce the amount of information you need to consider in your analysis: An Introduction to Programming with C++, Fifth Edition

  16. Analyzing the Problem (continued) • Worse than having too much information is not having enough information to solve problem: An Introduction to Programming with C++, Fifth Edition

  17. Analyzing the Problem (continued) • Distinguish between information that is missing and information that is implied: An Introduction to Programming with C++, Fifth Edition

  18. Planning the Algorithm • Algorithm: set of instructions that will transform the problem’s input into its output • Record it in the Processing column of the IPO chart • Processing item: intermediate value used by algorithm when processing input into output • Pseudocode is a tool programmers use to help them plan an algorithm • Short English statements An Introduction to Programming with C++, Fifth Edition

  19. Planning the Algorithm (continued) An Introduction to Programming with C++, Fifth Edition

  20. Planning the Algorithm (continued) • Flowcharts are also used to plan an algorithm • Use standardized symbols • Symbols connected with flowlines • Oval: start/stop symbol • Rectangle: process symbol • Represents tasks such as calculations • Parallelogram: input/output symbol • Represents I/O tasks An Introduction to Programming with C++, Fifth Edition

  21. Planning the Algorithm (continued) An Introduction to Programming with C++, Fifth Edition

  22. Planning the Algorithm (continued) • A problem can have more than one solution: An Introduction to Programming with C++, Fifth Edition

  23. Hints for Writing Algorithms This problem specification is almost identical to the one shown earlier in Figure 2-4 An Introduction to Programming with C++, Fifth Edition

  24. Hints for Writing Algorithms (continued) You may use a portion of a previous solution to solve current problem An Introduction to Programming with C++, Fifth Edition

  25. Desk-Checking the Algorithm An Introduction to Programming with C++, Fifth Edition

  26. Desk-Checking the Algorithm (continued) An Introduction to Programming with C++, Fifth Edition

  27. Desk-Checking the Algorithm (continued) • Valid data is data that the programmer is expecting the user to enter • Invalid data is data that he or she is not expecting the user to enter • You should test an algorithm with invalid data • Users may make mistakes when entering data An Introduction to Programming with C++, Fifth Edition

  28. The Gas Mileage Problem An Introduction to Programming with C++, Fifth Edition

  29. The Gas Mileage Problem (continued) • After planning the algorithm, you desk-check it: An Introduction to Programming with C++, Fifth Edition

  30. Summary • Problem-solving typically involves analyzing the problem, and then planning, reviewing, implementing, evaluating, and modifying (if necessary) the solution • Programmers use tools (IPO charts, pseudocode, flowcharts) to help them analyze problems and develop algorithms • During analysis, you determine the output and input • During planning, you write the steps that will transform the input into the output An Introduction to Programming with C++, Fifth Edition

  31. Summary (continued) • After the analysis and planning, you desk-check the algorithm • Follow each of the steps in algorithm by hand • Coding refers to translating the algorithm into a language that the computer can understand • Before writing an algorithm, consider whether you have already solved a similar problem An Introduction to Programming with C++, Fifth Edition

  32. Application Lesson: Using the First Steps in the Problem-Solving Process • Lab 2.1: Stop and Analyze • Lab 2.2: • Create a program that the salesclerks can use to calculate and display the required number of rolls • Lab 2.3: • The program must now display the number of single and double rolls of wallpaper • Lab 2.4: Desk-Check Lab • Lab 2.5: Debugging Lab An Introduction to Programming with C++, Fifth Edition

More Related