Transcript Week 1 - Session 1

EKT 120/4 : Computer
Programming
By:
Mr. Mohd. Nazrin Md. Isa
Contact me at :
04-9798410/[email protected]
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General Information
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Syllabus – refer handout
Contributes 4 units:
 2 hours - lectures
 4 hours – lab and tutorial
Main Objective:
 Students can independently write a computer
program to solve calculation problems,
especially those related to engineering
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Overall Evaluation
4 main components:
 Assignments (30%)
 1st & 2nd Test (15% +25%)
 Group Mini-project (30%)
 Assignments are individual lab
 The two tests are written tests
 Project : Max number of group member is 2
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References
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Text Book
 “ C Programming for
Engineering & Computer Science
” H.H.Tan and T.B.Orazio, Mc
Graw Hill, 1999.
References
 “C Programming”, Deitel &
Deitel
 “Problem Solving and
Programming Concept”, Maureen
Sprankle, 6th Ed.
 Any other C books
 WWW
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Notes
This course is NOT about the language per
se, it’s about problem solving / analytical
skills & to apply C to solve problems.
 Write C program in Linux environment
 Please do early reading
 Do not hesitate to ask during lecture
sessions
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Outline
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General Problem Solving Concept
 The six Steps in Problem Solving
Problem Solving Concepts for the Computer
 Computer Fundamental
 Data - Constant and Variable
 Data Type
Problem Solving Tool
 Problem Analysis Chart
 Structured Chart
 IPO Chart
 Algorithm
 Pseudocode and Flowchart
Software
 System Software
 Application Software
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General Problem Solving
Concept
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People make decisions every day that affect their lives.
Problems that we encounter every day may be important or
not so important (not so affected to our lives)
Generally there are six (6) steps in problem solving.
 Identify the Problem: What is the problem – in the
classroom usually problem is identified for you
 Understand the problem
 Identify alternative ways to solve the problem
 Select the best way to solve the problem
 List the instruction that enable you yo solve the
problem
 Evaluate the solution
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Understand the Problem
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Understand what is involved in the problem.
knowledge base of the person or machine
resources.
 For e.g. if for a person, we must know what the
person knows. Different set of instruction need
to be given for a different person, depending on
the knowledge base.
 E.g Direction of a place.
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Identify Alternative way
Identify several way, how to solve the
problem, but all this alternative way might
suitable to some people but not to some
other people.
 E.g. Direction to KWSP from Jejawi
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Select the best way of the alternative
solution
Here need to identify and evaluate the pros
and cons of each possible solution.
 Thus, we need to identify the criteria for the
evaluation as these criteria will serve as a
guidelines for the evaluation.
 E.g. Which is the fastest and shortest way to
KWSP from Jejawi.
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List the Instructions
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List down the step-by-step numbered instruction enable to solve the problem
using the selected solution.
All the instruction should be understand by the targeted person or the machine.
E.g
 1. go straight
 2. Will pass through round about
 3. Take 12 o’clock
 4. Up further, Until you reach junction with traffic light (where a police
station on your right)
 5. Take left.
 6. You will reach another junction, and take right.
 7. Go straight, you will see the KWSP building on your right.
 8. Go up further untill you reach a round abou and make U turn
 9. Go further until you reach KWSP building
 End
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Evaluate the Solution
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Check the result:
 Correct or not.
 Satisfy the need of the person or not
 Note: the result may be correct but not satisfy
the person
 E.g
 The steps you have directed the person might
be right, but the person does not drive.
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Example – A problem What to do this
evening
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Identify the problem: How do individual wish to
spend the evening.
Understand The problem:
 Knowledge base of people involve must be
considered
 So solution selected should be that everyone
involved would know haw to do.
 E.g we select play chess might not possible if
the participants does not know how to play
chess.
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Continue …
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Identify alternative
 Watch television, Invite friends over, Play
games, go outing. Complete the list until you
can’t find any more alternatives.
Select the best way to solve the problem
 Vote out alternatives that are not suitable, such
as costly, do not interest one of individual
involve etc.
Prepare the list of instruction.
Evaluate the solution. Everybody satisfy with the
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solution. Are we having fun? Etc.
Types of Problems
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Algorithmic Solution – problem can be solved
with a series of actions. So once we eliminate the
alternatives and have chosen one best methods,
these steps are called algorithm.
Heuristic Solution – Problem with solutions
require reasoning built on knowledge and
experience, and a process of trial and error.
Ussually use in the Artificial Intelligent software
or Expert system softwware.
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Problem Solving with Computer
Solution means the instructions that must
follow to produce the best results.
 Results mean the outcome or completed
computer – assisted answer.
 Program means the set of instructions that
make up the solution after they have been
coded into a particular computer language.
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Problem Solving Concept with Computer
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Computer Fundamental
 CPU – where all the processing take place
 Memory – store all data currently processed, before program can
be execute, program must be loaded into memory
 Input Device – Device use to input data to be processed into
computer
 Output Device – Device use to display processed data (output)
 Secondary Memory – Store permanent data (can be as output
device.
CPU
Output Device
Input Device
Main Memory
Secondary Memory
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Problem Solving Concept For
Computer
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Problem that can be solve with computers
generally consist of three:
 Computational – problem with mathematical
processing
 Logical – problem involving with relational or
logical processing. This is kind of processing
involve in decision making.
 Repetitive – problem involving repeating a set
of mathematical or logical instructions.
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Constant and Variable (Data)
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The most fundamental concept of problem solving for computer
Computer use constant and variable to solve problem. They are
actually the data used in the processing.
Constant:
 Value that never changes during the processing of all the
instructions.
 Can be any type of data – numerical, alphabetical, or special
symbols.
 constant is given a location in memory or a name.
 During the execution of the instructions (a program) this constant
is given a value and then is referred to by its name.
 Once the constant is given a value it cannot be changed during the
execution of the program.
 Example Pi = 3.14
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Continue …
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Variable:
 Value of a variable may changed during
processing
 Variable must have a name
 Programmer uses the variable name as a
reference name for a specific value of a
variable.
 the computer uses the name as a reference to
access that value in the computer memory
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Example Constant And Variable
Constant
Variable
Rule: Cannot be change.
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Example:
Value:
Rule:
“selamat datang”
Value:
Named Constant: Cannot be changed
after initially given a value. Storage
Loacation has
a name
3.142857
Example: Pi
Storage lacation given name
Values of the content can be change.
Refered by name in the instruction.
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Example
Variable Name – Age
Variable Name - Name
“Marina”
Value
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Data Types
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Data is unorganized facts, they go into computer as an input and are
processed by the program.
The outcome is the output or information in form of report or other
meaning full format to the user.
data uses are of many different types.
We need to tell the computer the type of data for each of the variable
used in the program.
The most common data types are numerical, character (alphabetical),
and logical.
Data
(Unorganized fact)
input
Computer
output
Data process
into
Infomation
Output
(report/information)
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Data Types Continue …
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Numerical Data:
 include all type of numbers. The only data used for calculation.
They are integers and real numbers
Character Data – Alphanumeric Data
 Consist of all single digit, letters, and special characters available
to the computer, e.g. a to z, A to Z, 3, #, & etc, placed within
quotation marks.
 Uppercase letter is different from the lowercase letter.
 can be compared and arranged in alphabetical order.
Logical
 consist of two pieces of data in the data set, TRUE and FALSE.
 There are use in making yes-no decision
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Example of Data Types
Data
Data Type
Explanation
The price of item:
7.55, 12.99
Numerical:
Real
Would be use in the calculation
An Account
Number:
“A444440”
Character:
String
Consist of alphanumeric or simply numbers,
cannot use in calculation
Quantity
Numerical:
integer
Use in calculation, Integer because normally as a
whole number
A date:
10/07/06
Date or Character
string
If date data type is available use date, unless use
character string
An answer to a
question:
True / False
Logical
An answer to question: Do you like coffee, is
either yes or no, therefore use logical
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Organizing The Problem
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There are several organizational tool can be used in
problem solving
 Problem Analysis Chart – the beginning analysis of the
problem
 Structured Chart – shows the overall layout or structure
of the solution
 IPO Chart – shows the input, the processing and the
output
Algorithm is the sequence of instructions comprising the
solution
Flowcharts is the graphic representations of the algorithm.
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Problem Analysis Chart (PAC)
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Consist of 4 separate parts
 Section 1 - The given data – Data given or provided by user, can be known
value or general name.
 Section 2 - The required result – Requirement for the output report,
information needed and th format required.
 Section 3 - The processing – List of processing required, include equation
or other type of processing, sort, searching and so forth.
 Section 4 - A list of solution – List of ideas for solution of the problem.
 Let consider Payroll problem calculating Gross Pay of a worker end of the
day.
Given Data
Required Result
Hours
Pay Rate
Gross Pay
Processing Required
Solution Alternative
Gross Pay = Hours * Pay Rate
1.
2.
Define the hours worked and pay rate as
constant
Define the hours worked and pay rate as
input values
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Structured Chart
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Divide the problem into subtasks called modules or smaller
subtasks.
This breakdown enable you to view complex problems. It
only shows you what will happen and not how its happen.
Use Top-Down Solution method
Main: PAYROLL
0000
READ
1000
CALC
2000
PRINT
3000
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IPO (Input-Processing-Output)
Chart
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IPO Extends and organizes the information in the problem analysis
chart.
Shows more detail what data items are inputs what processing takes
place on the data, and what
Input
All input data (section 1
of PAC)
Input
Hours Work
Pay rate
Processing
All processing in steps
(section 3 & 4 of PAC)
Processing
1. Enter hours work
2. Enter Pay rate
3. Calculate Pay
4. Print Pay
5. End
Module Reference
Number
Output
Module Reference from
structure chart
All output requirements
(section 1 & 2 from
PAC)
Module Reference
Number
Output
1000
1000
2000
3000
0000
Gross Pay
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Algorithms
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Organizing the solution where programmer develop a set
of instruction for the computer and this is call algorithm.
Pseudo code may be use, it is close to the actual
programming language that the programmer will used
later.
To complete it, the programmer will write another
separate set of instruction (coding/program) that will be
understand by the computer.
Instead of Pseudo code, we can also represent the set of
instruction in term of Flowchart ( a graphic presentation
of the algorithm.
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Algorithm-Basic symbols of
flowchart
Flowchart Symbol
Explanation
Flow lines
Flow of the direction
Start / Stop (terminator)
A start and an end of a module. For some end for a main
module and exit for other module
Processing
Processing block, for the calculation, and other step of
instructions.
Input / Output (I/O)
Input and output data to from the computer memory.
Decision
Usually has one entrance and two exit.
Process Module
A
counter
B
S
Automatic Counter loop
Connector
on page
Task that process in different place, module
The number of loop execute will start with A, counter
incremented by S, and until the end value B
off page
Flowchart can be sectioned, the connector will show
where the section continue
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Flowchart-(cont’d)
Algorithm
Main Module
1. Repeat
Process Read
Process Calc
Process Print
Until no more
employee
2. End
Flowchart
Algorithm
start
Read
Calc
Read Module
1000
1. Read Hours, Pay
rate
2. Exit
Flowchart
start
Read
Hours, Payrate
Print
false
exit
No more
employee
True
end
Algorithm
Calc Modul
2000
1. GrossPay = Hour
* payrate
2. Exit
Algorithm
start
GrossPay = Hours * Payrate
exit
Print Module
3000
1. Print Pay
2. Exit
Flowchart
start
Print
GrossPay
exit
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Software
Software is a program of the solution for a
specific task that programmer develop.
 In computer science software are classified
into :
 System software
 Application software
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Software
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System software : software manages the computer
and its peripheral devices (hardware)
 E.g. Operating systems(OS)
 Text editor
 Preprocessor
 Language translator
 Linker
 Loader
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Software
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Application software : performs specific tasks
There are two types:
 Program to solve specific problems
 Program written by user to solve specified
problem
E.g word processor, desktop publishing software,
spreadsheets, database, graphics, communication,
program perform a specific task such as
accounting, scientific, engineering, education etc
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Programming Languages
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Programming language is divided into three
categories:
 Machine Language
 Assembly Language
 High-Level Language
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Machine Language
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Language understood by the computer
Bunch of 0’s and 1’s
Program written in machine language can be
executed without being translated
Nevertheless, hard to learn because it is written in
0’s and 1’s
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Program is too long to solve simple problem
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Machine-dependant and not portable
E.g. 0101 1000 0101 1001 1100 0111
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
0101 0001 1100 0100 1011 1000
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Assembly Language
It is a low level programming language.
 To make it easier for the programmer, the
strings of 0’s and 1’s are replaced into
instructions which resembles English
language to represent computer operation
element
 So easier to understand and written
LOAD rate
 E.g
MULT hour
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STOR
wages
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Assembly Language
Nevertheless, need language translator
called Assembler to change Assembly
Language to Machine Code for execution
purpose
 Assembler is a type of system software, that
we use to translate our assembly code into
binary code (understand by computer.
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High-Level Language
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Example of high level programming language are,
PASCAL, C - Language, Java, Visual Basic etc
One instruction of it, consist several instructions in
machine level or assembly language.
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E.g. Grosspay := Hourswork * Payrate;
Before it can be executed by computer, the program must
be changed to machine code before executed. For high
level language compiler will translate the coding into
assembly code and binary code.
Compiler is a type of system software that we use to
compile our C code.
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Thank you
End of lecture #01
Any questions???
The following exercises are to be
completed during lab
1) Exercise 1
2) Exercise 2
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