1. Chapter 1 Introduction(1.1)

2. Objectives Introduction to Programming
Problem Solution and Software Development
Algorithms
C++ for Engineers and Scientists,

3. Introduction to Programming
Program: self-contained set of instructions used to operate a computer to produce a specific result
Also called software
Programming: the process of writing a program, or software
Programming language-The set of instruction that can be used to construct a program
C++ for Engineers and Scientists, Second Edition

4. Machine Language
Although the previous algorithm defines the steps for calculating the gross pay, it is not ready to be executed on the computer.
The computer only executes machine language instructions.

5. Machine Language
Machine language instructions are binary numbers, such as
Rather than writing programs in machine language, programmers use programming languages.

6. Programs and Programming Languages
Types of languages:
Low-level: used for communication with computer hardware directly. Often written in binary machine code (0’s/1’s) directly.
languages that use instructions tied directly to one type of computer
Examples: machine language, assembly language

7. -closer to human language
High-level:
-closer to human language
-instructions resemble written languages, such as English,and can be run on a variety of computer types
Examples: Visual Basic, C, C++, Java
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8. Introduction to Programming: Assembly Language (continued)
C++ for Engineers and Scientists, Second Edition

9. Introduction to Programming: Low- and High-Level Languages (continued)
Source code: the programs written in a high- or low-level language
Source code must be translated to machine instructions in one of two ways:
Interpreter: each statement is translated individually and executed immediately after translation
Compiler: all statements are translated and stored as an executable program, or object program; execution occurs later
C++ for Engineers and Scientists, Second Edition

10. Some Well-Known Programming Languages

11. Introduction to Programming: Low- and High-Level Languages (continued)
Large C++ programs may be stored in two or more separate program files due to
Use of previously written code
Use of code provided by the compiler
Modular design of the program (for reusability of components)
Linker: combines all of the compiled code required for the program
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12. Introduction to Programming: Procedural and Object Orientations (continued)
Figure 1.2 Creating an executable C++ program.
C++ for Engineers and Scientists, Second Edition

13. Example Algorithm for Calculating Gross Pay

14. From a High-level Program to an Executable File
Create file containing the program with a text editor.
Run preprocessor to convert source file directives to source code program statements.
Run compiler to convert source program into machine instructions.
Run linker to connect hardware-specific code to machine instructions, producing an executable file.
Steps b–d are often performed by a single command or button click.
Errors detected at any step will prevent execution of following steps.

15. Introduction to Programming: Application and System Software
Application software: programs written to perform particular tasks for users
System software: collection of programs to operate the computer system
System software must be loaded first; called booting the system
Bootstrap loader: a permanent, automatically executed component to start the boot process
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16. Introduction to Programming: Application and System Software (continued)
Operating system: the set of system programs used to operate and control a computer; also called OS
Tasks performed by the OS include
Memory management
Allocation of CPU time
Control of input and output
Management of secondary storage devices
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17. Introduction to Programming: The Development of C++
The purpose of most application programs is to process data to produce specific results
Figure 1.3 Basic procedural operations.
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18. Introduction to Programming: The Development of C++ (continued)
Early object-oriented language:
C++
C++ for Engineers and Scientists, Second Edition

19. Problem Solution and Software Development
Software development procedure: method for solving problems and creating software solutions
Consists of three phases:
Phase I: Development and Design
Phase II: Documentation
Phase III: Maintenance
Software engineering: discipline concerned with creating efficient, reliable, maintainable software
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20. Problem Solution and Software Development (continued)
Figure 1.6 The three phases of software development.
C++ for Engineers and Scientists, Second Edition

21. Problem Solution and Software Development: Phase I
Problem Solution and Software Development: Phase I. Development and Design
Program requirement: request for a program or a statement of a problem
After a program requirement is received, Phase I begins
Phase I consists of four steps:
Analysis
Design
Coding
Testing
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22. Problem Solution and Software Development: Phase I (continued)
Figure 1.7 The development and design steps.
C++ for Engineers and Scientists, Second Edition

23. Problem Solution and Software Development: Phase I (continued)
Step 1: Analyze the Problem
Analyst must understand
What outputs are required
What inputs will be needed
How the inputs can be used to produce the desired outputs
Failure to analyze and understand the requirements leads to a failed solution!
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24. Problem Solution and Software Development: Phase I (continued)
Step 2: Develop a Solution
Algorithm: the exact steps used to solve a problem
Algorithm is usually defined at high level, then refined to detailed lower levels
Structure level diagrams may be used to represent the levels of analysis
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25. Algorithms
Algorithm: the step-by-step sequence of instructions that describe how the data is to be processed to produce the desired output
Programming = the translation of the selected algorithm into a language the computer can use
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26. Algorithms (continued)
Pseudocode: English-like phrases used to describe the algorithm
Formula: description of a mathematical equation
Flowchart: diagram showing the flow of instructions in an algorithm
Flowcharts use special symbols
C++ for Engineers and Scientists, Second Edition

27. Problem Solution and Software Development: Phase I (continued)
Figure 1.8 First-level structure diagram.
C++ for Engineers and Scientists, Second Edition

28. Problem Solution and Software Development: Phase I (continued)
Figure 1.9 Second-level refinement structure diagram.
C++ for Engineers and Scientists, Second Edition

29. Problem Solution and Software Development: Phase I (continued)
Step 3: Code the Solution
Also called writing the program, and implementing the solution
Program should contain well-defined patterns or structures of the following types:
Sequence
Selection
Iteration
Invocation
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30. Problem Solution and Software Development: Phase I (continued)
Sequence: defines the order in which instructions are executed
Selection: allows a choice between different operations, based on some condition
Iteration: allows the same operation to be repeated based on some condition; also called looping or repetition
Invocation: involves invoking a set of statements when needed
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31. Problem Solution and Software Development: Phase I (continued)
Step 4: Test and Correct the Program
Testing: method to verify correctness and that requirements are met
Bug: a program error
Debugging: the process of locating an error, and correcting and verifying the correction
Testing may reveal errors, but does not guarantee the absence of errors
C++ for Engineers and Scientists, Second Edition

32. Problem Solution and Software Development: Phase I (continued)
Testing requires the use of meaningful, representative test data
Impossible to test all possible combinations of data and operations in a complex program
Testing plans must be developed to ensure good coverage in testing
Testing usually requires more time than other steps in Phase I
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33. Problem Solution and Software Development: Phase I (continued)
Relative effort for steps in Phase I
C++ for Engineers and Scientists, Second Edition

34. Problem Solution and Software Development: Phase II. Documentation
Many documents may be required, including
Program description
Algorithm development and changes
Well-commented program listing
Sample test runs
Users’ manual
C++ for Engineers and Scientists, Second Edition

35. Problem Solution and Software Development: Phase III. Maintenance
Maintenance includes
Ongoing correction of newly discovered bugs
Revisions to meet changing user needs
Addition of new features
Maintenance usually the longest phase, and may be the primary source of revenue
Good documentation vital for effective maintenance
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36. Problem Solution and Software Development: Backup
Backup: process of making copies of program code and documentation on a regular basis
Backup copies = insurance against loss or damage
Consider using off-site storage for additional protection
C++ for Engineers and Scientists, Second Edition

37. Integrated Development Environments (IDEs)
An integrated development environment, or IDE, combine all the tools needed to write, compile, and debug a program into a single software application.
Examples are Microsoft Visual C++, Borland C++ Builder, CodeWarrior, etc.

38. Integrated Development Environments (IDEs)

39. Summary Software: programs used to operate a computer
Programming language types:
Low-level languages
Machine language (executable) programs
Assembly languages
High-level languages
Compiler and interpreter languages
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40. Summary (continued)
Software engineering: discipline concerned with creating readable, efficient, reliable, and maintainable programs
Three phases in software development:
Program development and design
Documentation
Maintenance
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41. Summary (continued) Four steps in program development and design:
Analyze the problem
Develop a solution
Code the solution
Test and correct the solution
Algorithm: step-by-step procedure that describes how a task is performed
Computer program: self-contained unit of instructions and data used to operate a computer to produce a desired result
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42. Summary (continued) Sequence Selection Iteration Invocation
Four fundamental control structures used in coding:
Sequence
Selection
Iteration
Invocation
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43. Analyze and design(input, output, process) the solution (flowchart) for each of question
to read three numbers and find their product.
displays the area of a rectangle by accepting length and width from the user.
will read the radius of a circle and calculate and display its perimeter.
that will accept the radius of a circle and calculate and display its area
that will accept three numbers and calculate and display the total of the three.
that will accept the marks in a test for a group of 25 students then calculate and display the average mark.
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