King Saud University
College Of Applied Studies and Community Services
CSC 1101
Computer Programming-1
Done By: Asmal Alosaimi
Edited By: Noor Alhareqi & Alaa Altheneyan
CHAPTER 1
PSEUDOCODE & FLOWCHARTS
1st Semester 1433-1434 H
Levels of Program Development
2
1.
2.
3.
4.
5.
6.
Define the problem. Human thought
Plan the problem solution.  writing the
algorithm [pseudo-natural language (English,
Arabic) or drawing the flowchart diagram).
Code the program.  High Level
Programming Language (C, C++, Java, …)
Compile the program.  Machine Code
Run the program.
Test and debug the program.
Asma Alosaimi
From Lec1 we learn that
3

When planning for a problem solution, algorithms are
used to outline the solution steps using

English like statements, called pseudocode.
or

A flowchart , which is a graphical representation of
an algorithm.
Asma Alosaimi
Pseudocode
4

Pseudocode is a detailed description of what a
computer program must do, expressed in an English
like language rather than in a programming
language.
Asma Alosaimi
Pseudocode Example
5

1.
2.
3.
4.
5.
6.
Write a Program to Print the Sum of two integer
Numbers
Start the program
Read the first number and save in the variable ( N1 )
Read the second number and save in the variable (
N2 )
Sum the both numbers and save the result in the
variable ( Sum )  Sum = N1 + N2
Print the variable ( Sum )
End the program
Asma Alosaimi
Flowchart
6

A flowchart is a type of diagram that represents
an algorithm , showing the steps as boxes of various
kinds [ex: rectangles, diamonds, ovals], and their
order by connecting these with arrows.
Asma Alosaimi
Flowcharts Symbols
7
Start
Start/End
Read n1
Read/Print
End
Print n1
N2 = n1+3
n1 > 3
N2 = 5
Arithmetic Operations
Decision , can be used with loops
Solution
8
start
Draw a flowchart for a program that calculates
Read L, W
and print the area and the perimeter of
a rectangle.
area = L * W
 Input
 Length
 width
perimeter = 2 (L+W)
 Processing
 Area = length*width
Print area
 Perimeter = 2*( length + width)
Print perimeter
 Output
 Area
Asma Alosaimi
End
 Perimeter
Example 2
9

Draw the flow chart for a program that calculates
the total salary for an employee using this equation:
Total_Sal = Salary +Overtime
Asma Alosaimi
Solution
10



Input
 Salary
 Overtime
Processing
 Total_Sal = Salary +Overtime
Output
 Total_Sal
start
Read Salary
Read Overtime
Total_Sal =
Salary +Overtime
Print Total_Sal
Asma Alosaimi
End
Example 3
11




Draw a flowchart for a program that calculates and
prints the sum of the even integers from 2 to 30.
Input
 No input.
Processing
 Sum = 2+4+6+8+……+28+30.
Output
 sum
Asma Alosaimi
Solution
12
Pesudocode:






Start the program
Create a variable to hold a counter from 2 to 30.
Initialize the counter to 2.
Create a variable to hold the sum.
Initialize the sum to zero.
Loop While the counter is less-than-or-equal to 30





add the counter to the sum
add two to the counter.
repeat until the counter reach 30
Print the sum.
End of program
Asma Alosaimi
Solution
13
Start
Counter=2, Sum=0
no
yes
Counter≤30
yes
Sum= Sum + Counter
Counter=Counter+2
Print Sum
Asma Alosaimi
End
Example 4
14




Draw a flowchart for a program that determine if
the temperature degree is above or below freezing.
Input
 Temp.
Processing
 Check if Temp is below the 32  below freezing.
 Check if Temp is above the 32  above freezing.
Output
 Print “below freezing” or “above freezing”
Asma Alosaimi
Solution
15
Asma Alosaimi
Example 5
16

Draw a flowchart for a program that accepts a
person’s initial bank balance followed by a
sequence of numbers representing transactions. A
positive number represents a credit entry in the
account and a negative number represents a debit
entry. The input is terminated by a zero entry. The
program should print the new balance.
Asma Alosaimi
Solution
17



Input
 bank balance.
 transactions
Processing
 balance = balance + transaction.
Output
 balance
Asma Alosaimi
Solution
18
Start
Read balance
Read transaction
balance =balance + transaction
Transaction !=0
yes
no
Print balance
Asma Alosaimi
End
Example 6
19

Draw a flowchart for a program that calculates the
Zakat, where the user enter the amount of money
then the program show the zakat.
 Zakat
 Zakat
=(2.5/100) * amount.
is not calculated if the amount is less than 1000
S.R
Asma Alosaimi
Solution
20



Input
 amount.
Processing
 Check if amount is below 1000  Zakat =0.
 Check if amount is above 1000 Zakat =(2.5/100) *
amount
Output
 Zakat
Asma Alosaimi
Solution
21
Start
Read amount
no
yes
Amount > 1000
Zakat =0.
Zakat =(2.5/100)*amount
Print Zakat
Asma Alosaimi
End