1. CS-150 Problem Solving & Programming I with C++
Week 1: Overview
Tue/Thur January 13,
Textbook materials:
C++ Programming: From Problem Analysis to Program Design, 7th Edition ( 6th Ed.? )

2. New materials are being updated to our cs150 site,…

3. CS-150 Lecture – twice a week.
Catalog Course Description: Lecture 3 hours; Laboratory 2.5 hours; 4 credits Introduction to computer-based problem solving and programming in C++.
Topics include problem solving methodologies, program design, algorithm development, and testing.
C++ language concepts include variables, data types and expressions, assignment, control-flow statements, arrays, sorting, functions, pointers, and linked lists.
Lecture – twice a week.
Lab - once a week…required weekly, assignments.
Recitation –

4. Textbook
Malik, C++ Programming: from Problem Analysis to Programming Design , 7th edition Cengage Course Technology, Info on CS web site and ODU bookstore site.

5. Spring 2015 Session Dates:

6. Lab this week!
1)      REGISTER for YOUR CS accounts. You will need to log in using the guest account for the first lab. The Lab instructor will provide this information.
2)  Demo: how to download a CPP file for lab, create a CS150 folder in the Z drive, and create an organized structure so it’s easy to keep track of your work throughout the semester, e.g.:
3)  Practice opening, reviewing, compiling, & running a CPP file
z:\
z:\CS150\lab-assignment-1\lab-assignment-1.cpp

7. ******************************************************************************** CS150: Spring Lab Assignment Example Enter your first name: Stewie Enter your last name: Griffin Please confirm: Is your name Stewie Griffin? (Y/N): Y Enter today's date any way you like: Tuesday, 26 August 2014 Enter the year you were born: 2012 Your CS username is most likely: sgriffin You are probably turning 2 this year. Writing output to sgriffin-lab-assignment-1.txt. You can find it in the same folder as the CPP.

8. Teaching Assitants

9. Programming
Why? Fun!
Why?

10. A Brief Overview of the History of Computers
Early calculation devices
Abacus, Pascaline
Leibniz device
Babbage machines: difference and analytic engines
Hollerith machine
C++ Programming: From Problem Analysis to Program Design, Fourth, Fifth & Sixth Edition

11. Terminology
Algorithm: A set of steps that defines how a task is performed
Program: A representation of an algorithm
Programming: The process of developing a program
Software: Programs and algorithms
Hardware: Equipment

12. History of Algorithms
The study of algorithms was originally a subject in mathematics.
Early examples of algorithms
Long division algorithm
Euclidean Algorithm
Gödel's Incompleteness Theorem: Some problems cannot be solved by algorithms.

13. The Euclidean algorithm

14. Origins of Computing Machines
Greece, Ancient Assyria, Egypt,…..
The ABACUS most likely existed in Babylonia around 3000 B.C.
Abacus: positions of beads represent numbers

15. An Abacus

16. Early calculation devices
Abacus, Pascaline
Leibniz device
Jacquard’s weaving looms
Babbage machines: difference and analytic engines
Hollerith machine
Early computer-like machines
Mark I
ENIAC
Von Neumann architecture
UNIVAC
Transistors and microprocessors

17. Origins of Computing Machines
Gear-based machines (1600s-1800s)
Positions of gears represent numbers
Blaise Pascal, Wilhelm Leibniz, Charles Babbage
1622: invention of slide rule
1642: invention of mechanical calculator by Blaise Pascal
1694: Leibniz Wheel expands arithmetic operations

18. Charles Babbage Invents Difference Engine in 1823
Device adds, subtracts, multiplies, divides
Designs Analytical Engine
Incorporated components akin to modern computer systems: I/O devices, memory, CPU
Storage of programs in Babbage’s Analytical Engine - Gear positions
Ada Lovelace Byron
First programmer!
Program loop concept
Ada programming language namesake

19. Early Data Storage Stored Program Concept! Joseph Jacquard
First used in Jacquard Loom (1801) to store patterns for weaving cloth
Allows the operator to input and store parameters through use of punch cards that are oriented with selection pins.
Popular through the 1970’s
Similar to a player piano
Stored Program Concept!

20. The JACQUARD LOOM.
Note the long string of punch cards feeding into the machine.

22. Early Data Storage Herman Hollerith
Invented an electromechanical counter in 1880s.
Designed as a single-purpose machine, it was used in tabulating the 1890 US census.
Used punch cards as input

23. ….. IBM

24. Early Data Storage Herman Hollerith
The company created around this technology becomes International Business Machine: IBM
1944 – IBM Mark I computer
Mark I rapidly made obsolete by vacuum tubes.
This

25. The Mark I computer

26. Early Computers Based on mechanical relays Based on vacuum tubes
1940: Stibitz at Bell Laboratories
1944: Mark I: Howard Aiken and IBM at Harvard
Based on vacuum tubes
: Atanasoff-Berry at Iowa State
1940s: Colossus: secret German code-breaker
1940s: ENIAC: Mauchly & Eckert at U. of Penn.

27. Progress in Early Computers
Charles Sanders Peirce
His work with electric switches extends the work of Boole by emulating the true/false conditions of Boolean algebra
Benjamin Burack implements concepts in 1936 logic machine
John Atanasoff and Clifford Berry build a computer using vacuum tubes
Who is BOOLE?
NEXT SLIDE  What do you think was a major catalyst for advancement?

28. Categories of Computers
Mainframe computers
Midsize computers
Micro computers (personal computers)
Handheld devices
Appliances
?????
???
drones?
C++ Programming: From Problem Analysis to Program Design, 4th & 6th Edition

29. Elements of a Computer System
Hardware
Software: programs that do specific tasks
System programs control the computer
ex: Operating system
Application programs
Word processors
Spreadsheets
Games
CPU
Main memory: RAM
Input/output devices
Secondary storage

30. CPU (Central Processing Unit)
CU (Control Unit):
Fetches and decodes instructions
Controls flow of information in and out of MM
Controls operation of internal CPU components
PC (program counter): points to next instruction to be executed
IR (instruction register): holds instruction currently being executed
ALU (arithmetic logic unit): carries out all arithmetic and logical operations

31. Input devices
feed data & programs into computers
Keyboard
Mouse
Secondary storage
Output devices
display results
Monitor
Printer
Secondary storage

32. Main Memory Directly connected to the CPU
All programs loaded here before execution
All data must be brought here before use
Power off == data in main memory is lost

33. Secondary Storage
Secondary storage: device that stores information permanently
Examples of secondary storage:
Hard disks
Flash drives
Floppy disks
Zip disks
CD-ROMs
Tapes ?

34. The Language of a Computer
Digital signals are sequences of 0s and 1s
Binary code: - A sequence of 0s and 1s
Machine language: language of a computer
Bit: (binary digit) : The digit 0 or 1
Byte: A sequence of eight bits

37. Coding Schemes
ASCII (American Standard Code for Information Interchange)
128 characters
A is encoded as (66th character)
3 is encoded as
C++ Programming: From Problem Analysis to Program Design, Fourth Edition

38. Coding Schemes (continued)
EBCDIC
Used by IBM
256 characters
Unicode
65536 characters
Two bytes are needed to store a character
C++ Programming: From Problem Analysis to Program Design, Fourth Edition

39. Evolution of Programming Languages
Early computers were programmed in machine language
To calculate wages = rates * hours in machine language:
//Load
//Multiply
//Store

40. Assembly Language Assembly language instructions are mnemonic
Assembler: translates a program written in assembly language into machine language

41. High-Level Languages
High-level languages include Basic, FORTRAN, COBOL, Pascal, C, C++, C#, and Java, ect..
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;

42. What?
Meanwhile,… back in class,….

43. Outline Computer Programming Process
Algorithms and programming languages

44. Computer Programming Computer program
A sequence of instructions to be performed by a computer
Computer programming
The process of planning a sequence of steps for a computer to follow
Programming Process
Problem-solving phase
Implementation phase
Maintenance phase

45. Programming Process1/3 Problem-solving phase
Analysis and specification ( understand and define problem, and what is expected of solution)
General solution (algorithm: a logical sequence of steps that solves the problem)
Verification (Follow steps to make sure solution solves the problem)
Implementation phase
Concrete solution (Program in a Programming language)
Testing (make sure the program produces the desired results)
Maintenance phase
Use Program
Maintain Program (meet changing requirements)

46. Documentation: writing program documentation, and user manuals
Programming Process2/3
Analysis and Specification
Concrete solution
(Program)
General solution (algorithm)
Testing
Verification
Maintenance Phase
Documentation: writing program documentation, and user manuals
In “Programming and Problem Solving with C++”, 3rd Edition, Jones and Bartlett Publishers, 2002

47. Programming Process3/3
How about we take a shortcut and start the programming process by the implementation phase?
Costly shortcut
Develop a general solution (algorithm) first
Think first and code later!

48. Algorithm1/3
Algorithm
An ordered set of unambiguous executable steps, defining a terminating process
A step-by-step procedure for solving a problem in a finite amount of time
Make a list of all positive integers
Arrange the list in descending order (from largest to smallest)
Extract the first integer from the list
What are the problems with these instructions?

49. Algorithm2/3
Difference between an algorithm and its representation
Analogous to difference between a story and a book
An algorithm is abstract and can be represented in many ways
Algorithm for converting from Celsius to Fahrenheit can be represented as
1. F = (9/5) C + 32 (algebraic equation)
2. “ Multiply the temperature reading in Celsius by 9/5 and then add 32 to the product”
An algorithm can be represented using some sort of language
1950s, 1960s  represented using flowcharts
pseudocode (precisely defined textual structures)

50. Algorithm3/3 An algorithm for starting the car
Insert the key in ignition
Make sure transmission is in Park (or Neutral)
Depress the gas pedal
Turn key to start position
If engine starts within six seconds, release key to ignition position
If engine does not start in six seconds, release key and gas pedal, wait ten seconds, and repeat steps 3 through 6, but not more than five times
If the car does not start, call the garage

51. Programming Language1/3
A set of rules, symbols, and special words used to construct a computer program. There are rules for syntax (grammar) and semantics (meaning)
Machine language
Binary-coded instructions
Closely coupled with design of computer hardware
Assembly language
Low-level programming language in which a mnemonic is used to represent each of the machine language instructions
We have seen an example in chapter 2 from Brookshear Text
We need an assembler
Translate an assembly language program into machine code

52. Programming Language2/3
High-level language
closer to English and other natural languages
C++, Java, C, Fortran, Ada, Pascal, COBOL, BASIC
We need a compiler
Translate a high-level language program into machine code
Source program
Program written in a high-level language
Object program
Machine language version of a source program
Difference between compilation and execution of a program

53. Programming Language3/3
Some programming languages are translated by an interpreter (some versions of BASIC)
Interpreter translates and executes each instruction in the source program
Java uses both a compiler and interpreter

54. A C++ Program My first C++ program. The sum of 2 and 3 = 5 7 + 8 = 15
#include <iostream>
using namespace std;
int main() {
cout << "My first C++ program." << endl;
cout << "The sum of 2 and 3 = " << 5 << endl;
cout << "7 + 8 = " << << endl;
return 0; }
Sample Run:
My first C++ program.
The sum of 2 and 3 = 5
7 + 8 = 15

55. Processing a Program To execute a C++ program:
Use an editor to create a source program in C++
Preprocessor directives begin with # and are processed by the preprocessor
Use the compiler to:
Check that the program obeys the rules
Translate into machine language (object program)
Software Development Kit (SDK) may be used to create a program

56. Processing a Program (contd) To execute a C++ program (continued):
Linker:
Combines object program with other programs provided by the SDK to create executable code
Loader:
Loads executable program into main memory
The last step is to execute the program

58. Programming is a process of problem solving

59. Programming with the Problem Analysis–Coding–Execution Cycle
Programming is a process of problem solving
One problem-solving technique:
Analyze the problem
Outline the problem requirements
Design steps (algorithm) to solve the problem
Algorithm:
Step-by-step problem-solving process
Solution achieved in finite amount of time

60. Programming with the Problem Analysis–Coding–Execution Cycle
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 - Maintenance
Use & modify the program if problem domain changes

62. Analyze the Problem Thoroughly understand the problem
Understand problem requirements
Does program require user interaction?
Does program manipulate data?
What is the output?
If the problem is complex, divide it into subproblems
Analyze each sub-problem as above

63. Design an Algorithm If problem was broken into subproblems
Design algorithms for each subproblem
Check the correctness of algorithm
Can test using sample data
Some mathematical analysis might be required

64. Problem Solving Techniques
You follow algorithms every day in your life
We need to learn how to design algorithms not simply follow them
Some Strategies to solve problems
Ask questions
Look for things that are familiar
Means-Ends Analysis
Divide and Conquer

65. Strategies: Ask Questions
When you are given a problem, you ask questions (What, Why, When, and Where?)
In the context of programming
What do I have to work with (What is my data)?
What do the data items look like?
How much data is there?
How will I know when I have processed all the data?
What should my output look like?
How many times is the process going to be repeated?
What special error conditions might come up?

66. Strategies: Look for Familiar Things
Never reinvent the wheel
If a solution exists  USE IT
Finding the daily high and low temperatures
is really the same problem as
Finding the highest and lowest grades on a test
Both problems can be abstracted as being
Find largest and smallest values in a set of numbers

67. Strategies: Means-Ends Analysis
Beginning state and End state are often given
You need to define a set of actions that can be used to get from one to the other
Once you have a set of actions, you need to work out the details
Translated to computer programming
Begin by writing down what the input is? (Beginning state)
What the output should be? (End state)
What actions can be performed to obtain results from input data?

68. Strategies: Divide and Conquer
Break up large problems into smaller problems that are easier to handle
(Top-Down approach)
Hard problem
Easy subproblem
Hard subproblem
Easy subproblem
Easy subproblem
Easy subproblem

69. An Example1/3 Compute the area of a circle
Problem statement - We need an interactive program (user will input data) that computes the area of a circle. Given the circle radius, the circle area should be displayed on the screen
Input/Output description
Input  Circle radius
Output  Circle area
Algorithm development (set of steps, decomposition outline)
Read value of circle radius (r)
Compute circle area as pi * r2
Print the value of circle area
How do we represent more complex algorithms?
Pseudocode, flowcharts (will introduce flowcharts later)

70. An Example2/3 A divide and conquer block diagram of our problem
Circle area
Read radius
Print circle area
Compute area
Pseudocode
Prompt the user for the circle radius (put a message on the screen)
Read radius
Assign Circle area the value pi * radius2
Write Circle area on the screen
Stop

71. An Example3/3 Convert algorithm into a C++ program
#include <iostream.h>
void main () {
float pi = f;
float radius, area;
cout << "Enter the radius of the circle: ";
cin >> radius;
area = pi* radius * radius;
cout << "The area of the circle is: " << area << endl; }

72. Write the Code Once the algorithm is designed and correctness verified
Write the equivalent code in high-level language
Enter the program using text editor

73. Compiling and Linking Run code through compiler
If compiler generates errors
Look at code and remove errors
Run code again through compiler
If there are no syntax errors
Compiler generates equivalent machine code
Linker links machine code with system resources

74. The Loader and Executing
Once compiled and linked, loader can place program into main memory for execution
The final step is to execute the program
Compiler guarantees that the program follows the rules of the language
Does not guarantee that the program will run correctly

75. Create a program to determine the perimeter and area of a rectangle
Example 1-1
Create a program to determine the perimeter and area of a rectangle

76. Example 1 Analyze the Problem
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

77. Example 1 Design the 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
- Display the results:

78. Example 1 Write the Code PsuedoCode cin length // Input length
cin width // Input width
perimeter=2*(length + width) // Calc #1
area = length * width // Calc #2
cout perimeter // Output width
cout area // Output width
PsuedoCode

79. Compiling and Linking
Codeblocks

80. Programming Methodologies
Two popular approaches to programming design
Structured
Object-oriented

81. 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

82. Object-Oriented Programming
Identify components called objects
Specify relevant data and possible operations to be performed on that data
Each object consists of data and operations on that data
An object combines data and operations on the data into a single unit

83. Object-Oriented Programming (continued)
A programming language that implements OOD is called an object-oriented programming (OOP) language
Learn how to represent data in computer memory, how to manipulate data, and how to implement operations
Write algorithms and implement them in a programming language

84. Object-Oriented Programming (continued)
Learn how to combine data and operations on the data into a single unit called an object
C++ was designed to implement OOD
OOD is used with structured design

85. ANSI/ISO Standard C++ C++ evolved from C
C++ designed by Bjarne Stroustrup at Bell Laboratories in early 1980s
C++ programs were not always portable from one compiler to another
In mid-1998, ANSI/ISO C++ language standards were approved

86. Summary
Computer: electronic device that can perform arithmetic and logical operations
Computer system has hardware and software
Central processing unit (CPU): brain
Primary storage (MM) is volatile; secondary storage (e.g., disk) is permanent
Operating system monitors the overall activity of the computer and provides services

87. Summary (continued)
Various kinds of languages, such as machine language, assembly, high-level
Algorithm: step-by-step problem-solving process; solution in finite amount of time
Problem-solving process has three steps:
Analyze problem and design an algorithm
Implement the algorithm in code
Maintain the program

88. Summary (continued) Structured design:
Problem is divided into smaller subproblems
Each subproblem is solved
Combine solutions to all subproblems
Object-oriented design (OOD): a program is a collection of interacting objects
Object: data and operations on those data