egr 2261 engineering problem solving using c and c++ professor nick reeder

EGR 2261

Engineering Problem Solving Using C and C++

Professor Nick Reeder

Reminders

Please turn off cell phones.

No food or soft drinks in the classroom.

Stow water bottles at floor level.

EGR 2261 Unit 1Overview

Read Malik, Chapter 1. Homework #1 and Lab #1 due next

week. Quiz next week.

Chapter 1:An Overview of Computers and

Programming Languages

Introduction

• Without software, the computer is useless.• Software is developed with programming languages.• C++ is one of the most popular programming

languages.– TIOBE Index– LangPop.com– IEEE

• C++ is suited for a wide variety of programming tasks.

5C++ Programming: From Problem Analysis to Program Design, Seventh Edition

C++ Versus C

• C++ evolved from C, and you can think of C as being a subset of C++.• So in learning C++, you’re also learning C

(and then some).

• Other popular languages that evolved from C include Java, C#, Objective-C.

C++C

Elements of a Computer System

• Hardware– CPU– Main memory– Secondary storage– Input/Output devices

• Software

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Central Processing Unit and Main Memory

• Central processing unit– Brain of the computer– Most expensive piece of

hardware– Carries out arithmetic and

logical operations

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Central Processing Unit and Main Memory (cont’d.)

• Main memory– Directly connected to the CPU

• All programs must be loaded into main memory before they can be executed.

• All data must be brought into main memory before it can be manipulated.

• When computer power is turned off, everything in main memory is lost.

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Central Processing Unit and Main Memory (cont’d.)

• Main memory is an ordered sequence of memory cells.– Each cell has a unique location in main memory, called the

address of the cell.

• Each cell can contain either a programming instruction or data.

10C++ Programming: From Problem Analysis to Program Design, Seventh Edition

Secondary Storage

• Secondary storage: device that stores information permanently

• Examples of secondary storage:– Hard disks – Flash drives– Floppy disks– Zip disks– CD-ROMs– Tapes

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Input/Output Devices

• Input devices feed data and programs into computers.– Keyboard – Mouse

• Output devices display results.– Monitor– Printer

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Software

• Software: programs that do specific tasks.• System programs control the computer.

– Operating system monitors the overall activity of the computer and provides services such as:

• Memory management• Input/output activities• Storage management

• Application programs perform a specific task.– Word processors– Spreadsheets– Games

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The Language of a Computer

• Digital devices (computers, iPods, cell phones, …) use binary code to represent information. This means they store all information (numbers, text, images, music, …) as sequences of 0s and 1s.

• Each 0 or 1 in such a sequence is called a bit (short for binary digit).

• Example of an 8-bit sequence: 01101100• A typical song in an MP3 file might

contain 40 million bits.

The Language of a Computer (cont’d.)

• Byte:– A sequence of eight bits

• Kilobyte (KB): 210 bytes = 1024 bytes• Table 1-1 on page 6 (next slide) shows some other

related terms.• This is useful general information, but not critical to

what we’ll do in this course.

15C++ Programming: From Problem Analysis to Program Design, Seventh Edition

16C++ Programming: From Problem Analysis to Program Design, Seventh Edition

The Language of a Computer (cont’d.)

The Language of a Computer (cont’d.)

• At least three different encodings have been used to represent text as sequences of 0s and 1s.

• ASCII (American Standard Code for Information Interchange) – 128 characters; see Appendix C in textbook.

• EBCDIC– Formerly used by IBM; obsolete.

• Unicode – 65,536 characters; covers most modern alphabets.

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The Evolution of Programming Languages

• Early computers were programmed in machine language., which required the programmer to type sequences of 0s and 1s.

• To calculate wages = rate * hours in machine language:

100100 010001 //Load

100110 010010 //Multiply

100010 010011 //Store

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The Evolution of Programming Languages (cont’d.)

• Assembly language replaces sequences of 0s and 1s with mnemonics (abbreviations such as LOAD or MULT).

• Using assembly language instructions, wages = rate * hours can be written as:

LOAD rateMULT hourSTOR wages

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The Evolution of Programming Languages (cont’d.)

• High-level languages include Basic, FORTRAN, COBOL, Pascal, C, C++, C#, and Java. Programs written in these language look much more like English.

• Compiler: translates a program written in a high-level language into machine language.

• The equation wages = rate * hours can be written in C++ as: wages = rate * hours;

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Microsoft Visual Studio

• In this course you’ll use Microsoft Visual Studio Community 2015 to enter, run, and test your programs.

• This is a free version of Visual Studio that you can install at home. Instructions on course website.

• It’s powerful, complex software used by professional programmers.

A Simple C++ Program//***************************************************// Name: SimpleWageProgram// Author: Nick Reeder // Date: 07/13/2015 // Computes weekly wages.//***************************************************#include <iostream>using namespace std;int main() { int rate = 15; int hours = 40; int wages = rate * hours; cout << wages << endl;

return 0;}

22C++ Programming: From Problem Analysis to Program Design, Seventh Edition

Parentheses, Braces, and Brackets

• C++ uses the following symbols to enclose code:• Parentheses ( )• Braces { }• Square brackets [ ]• Angle brackets < >

• Each pair of symbols has a specific use. They are not interchangeable. You can’t use parentheses where you’re supposed to use braces, and so on.

Processing a C++ Program

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Processing a C++ Program (cont’d.)

• Steps in processing a C++ program:– Use an editor to create source

code in C++.– Preprocessor directives begin

with # and are processed by the preprocessor.

– Compiler:• Checks that the program obeys

the language rules.• Translates into machine

language (object program).

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Processing a C++ Program (cont’d.)

• Steps in processing a C++ program (cont’d.):– Linker:

• Combines object program with other files to create executable code.

• Library: contains prewritten code you can use.

– Loader: • Loads executable program into

main memory.

– The last step is to execute the program.

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Integrated Development Environement

• In the old days you might need several computer programs to perform all of the steps listed above. But Visual Studio combines all of these into a single program. It’s an example of an Integrated Development Environment (IDE).

• Another popular free C++ IDE is Bloodshed’s Dev-C++ at http://www.bloodshed.net/devcpp.html.

Programming with the Problem Analysis–Coding–Execution Cycle

• Algorithm: – Step-by-step problem-solving

process– Solution achieved in finite

amount of time

• Programming is a process of problem solving.

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The Problem Analysis–Coding–Execution Cycle (cont’d.)

• Step 1: Analyze the problem.– Outline the problem and its requirements.– Design steps (algorithm) to solve the problem.

• Step 2: Implement the algorithm.– Implement the algorithm in code.– Verify that the algorithm works.

• Step 3: Maintain.– Use and modify the program if the problem domain

changes.

29C++ Programming: From Problem Analysis to Program Design, Seventh Edition

Example 1-1

• Design an algorithm to find the perimeter and area of a rectangle.

• The perimeter and area of the rectangle are given by the following formulas:

perimeter = 2 * (length + width)area = length * width

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Example 1-1 (cont’d.)

• Algorithm:– Get length of the rectangle.

– Get width of the rectangle.

– Find the perimeter using the following equation:

perimeter = 2 * (length + width)

– Find the area using the following equation:

area = length * width

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Programming Methodologies

• Two popular approaches to programming design:– Structured– Object-oriented

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Structured Programming

• Structured design: – Dividing a problem into smaller subproblems.

• Structured programming:– Implementing a structured design.

• The structured design approach is also called:– Top-down (or bottom-up) design– Stepwise refinement– Modular programming

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Object-Oriented Programming

• Object-oriented design (OOD)– Identify components called objects.– Determine how objects interact with each other.

• Specify relevant data and possible operations to be performed on that data.

• Each object consists of data and operations on that data.

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Object-Oriented Programming (cont’d.)

• An object combines data and operations on the data into a single unit.

• A programming language that implements OOD is called an object-oriented programming (OOP) language.

• Must learn how to represent data in computer memory, how to manipulate data, and how to implement operations .

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Object-Oriented Programming (cont’d.)

• Write algorithms and implement them in a programming language.

• Use functions to implement algorithms.• Learn how to combine data and operations on the

data into a single unit called an object.• C++ was designed to implement OOD.

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ANSI/ISO Standard C++

• C++ evolved from C .• C++ designed by Bjarne Stroustrup at Bell

Laboratories in early 1980s.– Many different C++ compilers were available.– C++ programs were not always portable from one compiler

to another.

• In 1998, ANSI/ISO C++ language standards were approved.

• Second standard called C++11 approved in 2011.

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