1. F1001 PROGRAMMING FUNDAMENTALS
UNIT
2
PROBLEM SOLVING
 Programming Life Cycle
 Program Design
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2. F1001 PROGRAMMING FUNDAMENTALS
PROGRAMMING LIFE CYCLE
• Life Cycle: Refers to the changes made from an old to a new program (the cycle starts again).
• Programming Life Cycle: A framework or discipline, which uses certain techniques needed in
computer programming development.
• Steps involved in programming life cycle:
PROBLEM ANALYSIS
PROGRAM DESIGN
PROGRAM CODING
TESTING AND DEBUGGING
MAINTENANCE
DOCUMENTATION
STEP 1: PROBLEM ANALYSIS
Purpose:
• To describe in detail a solution to a problem and information needed in solving the problem.
How?
• Study and understand the problem.
• Identify:
o The needed input.
o The required output.
o The needed process. For example: scientific formula or particular theories.
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3. F1001 PROGRAMMING FUNDAMENTALS
Problem 1: Write a program that will get 3 numbers as input from the users. Find the average and
display the three numbers and its average.
Problem Analysis:
Input: 3 numbers.
Process: 1. Add the three numbers
2. Divide the total of the three numbers with 3
Output: The three numbers and its average
INPUT PROCESS OUTPUT
STEP 2: PROGRAM DESIGN
• Definition: It is a framework or flow that shows the steps in problem solving.
• Methods to design a program:
1. Algorithm
 Algorithm is a sequence of instructions to solve a problem, written in human language, and it
can solve any problems when it is used with the correct procedure.
 A programmer writes the problem solving in the form of an algorithm before coding it into
computer language.
 Example of algorithm to calculate the average of three numbers:
1. Set Total=0, Average=0;
2. Input 3 numbers
3. Total up the 3 numbers
Total= total of 3 numbers
4. Calculate average
Average=Total/3
5. Display 3 numbers and the average
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4. F1001 PROGRAMMING FUNDAMENTALS
2. Flowchart
• A graphical representation of data, information and workflow using certain symbols that are
connected to flow lines to describe the instructions done in problem solving.
• It shows the flow of the process from the start to the end of the problem solving.
Carta alir / Flowchart Penerangan / Explanation
START
• Enter data from keyboard
• Calculate total
Input
• Display data and total
Process
Output
END
• Explanation of basic flowchart symbol:
Simbol / Symbol Penerangan / Explanation Algorithma / Algorithm
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Decision

5. F1001 PROGRAMMING FUNDAMENTALS
 Indicate the direction of data flow.
 Used to connect a block to another
block.
Flow Lines
 Indicates operations / process  Variable = instruction
involved.
Process
 Receive / read value  Input (list out variable names)
 Display value  Output (result)
Input / Output
<execute instruction that does not
 Execute decision based on
fulfil the condition>
condition.
 Test is performed and the program
flow continues, based on the result.
 Indicates the beginning and end of  START
START
a flowchart.  END
Start / End
Flow Lines
Input
 Show the continuing flowchart in
the same page.
On-page
connector True
Condition True Statement
False
False statement
Outpu
t
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END

6. F1001 PROGRAMMING FUNDAMENTALS
Symbol Usage
Symbol Explanation
 Flowchart continues in the next
page.
Off Page
Connector
START
B
Input
Outpu
t
Process
END
B Next page
First page
Symbol Usage
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7. F1001 PROGRAMMING FUNDAMENTALS
• There are few additional symbols of flowchart used in a complicated program: GOSUB and
RETURN. It’s usually used in a big program.
Symbol Explanation
 Instruct the executed instruction to
move to the next function
GOSUB
 Instruct the executed instruction to
return to the next instruction after
the GOSUB instruction, called the
RETURN
function.
START area
Input area =22 / 7 * radius * radius
radius
GOSUB Output
area area
END RETURN
Symbol Usage
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8. F1001 PROGRAMMING FUNDAMENTALS
• Example Flowchart:
Flowchart to calculate the total of fine for late returning of library books.
START
Input
total_of_day
Fine = total_of_day * 0.20
Output Fine
Symbol Usage
3. Pseudocode
• Steps in problem solving that is END half in programming code and half in human
written
language.
• For example, some part uses C language code and some part uses Malay or English language.
• Advantages:
 Easily understood.
 Easily maintained.
 The codes are changeable.
• Disadvantages:
 Cannot be executed in the computer.
• Example:
START
Total=0, Average=0
Input a, b, c
Total = a + b + c
Average = Total / 3
Output a, b, c
Output Average
END
4. Structure Charts
• Structure chart is an additional method in preparing programs that has many sub modules.
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9. F1001 PROGRAMMING FUNDAMENTALS
• It consists rectangular boxes, which represents all the sub modules in a program and is connected
by arrows.
• It illustrates the top-down design of a program and is also known as hierarchical chart because its
components are in hierarchical form.
• The advantage is that it is easy to be drawn and to be changed.
• Format:
MainModule
SubModule 1 SubModule 2 SubModule 3
• Example 1: SubModule 2.1
SubModule 2.2
 Problem: To calculate the amount of water bill
Water bill
Display Determine
Get / read Compute Display Print
instructions the late
data the charge the bill the bill
for user charge
Represent the modules in the program
• Example 2:
 Problem: To calculate area of a circle
 Structure Charts: Area of a circle
Display Print
instructions Get / read Compute Define Display
the
for user data the area the area the area
area
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Represent the modules in the program

10. F1001 PROGRAMMING FUNDAMENTALS
STEPS 3: PROGRAM CODING
• Definition: Writing problem solving into certain programming language such as C, COBOL and
others.
• Problem solving: Instructions before it is coded into programming language.
• Purpose: To produce a program to develop a system.
# include <stdio.h>
main( )
{
int a, b, c, Total;
Example of syntax in C double Average;
language to display Total=0, Average=0
instruction for user to printf(" Enter 3 numbers:");
enter 3 numbers on scanf("%d %d %d",&a, &b, &c);
computer screen. Total = a + b + c;
Average = Total / 3;
printf("a = %d b = %d c = %d ", a, b, c);
printf("Average is = %f", Average);
return 0;
}
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11. F1001 PROGRAMMING FUNDAMENTALS
STEP 4: TESTING AND DEBUGGING
• Definition of Testing:
 Using a set of data to discover errors and to ensure accuracy of the program.
• Testing Process:
 Diagram indicates the process of testing:
Input sample of Output (functioning well or
Executing Program
error discovered)
data set
• Example 1:
Assume that a program to find the average of 3 numbers has been coded. Then, execute the program.
Using a few numbers, test the program to verify whether the result is as expected.
Testing 1:
Input: 4,5,8
Testing 2: From the output, has the program produced the expected result?
Input: 7,8,6
 An error is known as bug.
 Debugging is a process of identifying and correcting error.
• Two types of error:
1. Syntax Error (grammatical error)
 Occurs when the rules of programming language are not applied.
 Correction is done during the program coding.
 The bug can be traced during the compilation.
 Also known as compile-time error
 Must be corrected before executing and testing the program.
2. Logic error
 Cannot be traced by compiler.
Syntax error will occur if
 Corrected during the problem solving process.
there is any mistake in the
 Also known as run time error.
program.
 Example output for average is 4, but when it runs, the output is 2.
Example:
No semicolon at the end
of the instruction.
Syntax error message
Line 9 where syntax error 27
occurred.
SYNTAX ERROR

12. F1001 PROGRAMMING FUNDAMENTALS
- Logic error is an error that occurs
# include <stdio.h>
because logical statement in program
main( )
is wrong
{
- Example:
int a, b, c, Total;
Sum is total of the 3 numbers.
double Average;
Supposedly the average is sum / 3
Total=0, Average=0
because there are 3 numbers.
printf(" Enter 3 numbers:");
scanf("%d %d %d",&a, &b, &c);
Total = a + b + c;
Average = Total / 6;
printf("a = %d b = %d c = %d ", a, b, c);
printf("Average is = %f", Average);
return 0; Logic Error
}
The wrong Input three numbers:
444 LOGIC ERROR
output
Average of the
numbers: 2
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13. F1001 PROGRAMMING FUNDAMENTALS
STEP 5: MAINTENANCE
Definition:
• Activity that verifies whether the operational system is performing as planned or an activity to modify
the system to meet the current requirement.
• The process of changing a system after it has been applied to maintain its ability. The changes may
involve simple changes such as error correcting.
How to do maintenance?
• By performing activities such as:
o Testing – Test the ability of the system.
o Measurement – Access data time. Example, time to save, print and others.
o Replacement – Replace the old system to new system.
o Adjustment – Adding needs to new system.
o Repair – For example: An old system cannot update the new data
o Updating – Update the database.
• Example: Maintenance of Telecommunication System TELEKOM.
o Telecommunication System TELEKOM provides communication service from one house to
another house. The telephone number is 7 digits.
o Assume that management will change the number of digit from 7 digits to 8 digits.
o Programmer will change the old system to a new system and test the system whether it is
functioning well or not.
o Then, the new systems overall capability will be tested. For example, the capability to
identify the caller’s and the user’s location and time taken to connect them (measurement)
will be tested.
o Any old function that is no longer used will be replaced with a new function (replacement).
STEP 6: DOCUMENTATION
Definition: A written or graphical report of the steps taken during the development of a program.
Purpose: It will be useful in the future, in case of modification or maintenance.
Content of Documentation:
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14. F1001 PROGRAMMING FUNDAMENTALS
o Description of the program.
o Specification of program requirement
o Program design such as pseudocode and flowchart
o List of program and comments (to explain about the program).
o Test results.
o User’s manual book.
o Program capabilities and limitation.
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