1. Chapter 1 Pseudocode & Flowcharts
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 H

2. Levels of Program Development
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.
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3. From Lec1 we learn that
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.
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4. Pseudocode
Pseudocode is a detailed description of what a computer program must do, expressed in an English like language rather than in a programming language.
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5. Pseudocode Example
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
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6. Flowchart
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. 
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7. Flowcharts Symbols Start/End Start End Read/Print Print n1 Read n1
Arithmetic Operations
N2 = n1+3
N2 = 5
Decision , can be used with loops
n1 > 3

8. Solution start Draw a flowchart for a program that calculates
and print the area and the perimeter of
a rectangle.
Input
Length
width
Processing
Area = length*width
Perimeter = 2*( length + width)
Output
Area
Perimeter
Read L, W
area = L * W
perimeter = 2 (L+W)
Print area
Print perimeter
End
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9. Total_Sal = Salary +Overtime
Example 2
Draw the flow chart for a program that calculates the total salary for an employee using this equation:
Total_Sal = Salary +Overtime
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10. Solution start Input Salary Overtime Processing Read Salary
Total_Sal = Salary +Overtime
Output
Total_Sal
Read Salary
Read Overtime
Total_Sal =
Salary +Overtime
Print Total_Sal
End
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11. Example 3
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 = ……
Output
sum
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12. Solution 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
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13. Solution no Start Counter=2, Sum=0 yes Counter≤30 yes
End
Counter=2, Sum=0
Counter≤30
Sum= Sum + Counter
Counter=Counter+2
Print Sum
yes no
yes
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14. Example 4
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”
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15. Solution
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16. Example 5
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.
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17. Solution Input bank balance. transactions Processing
balance = balance + transaction.
Output
balance
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18. balance =balance + transaction
Solution
Start
Read balance
Read transaction
balance =balance + transaction
Transaction !=0
yes no
Print balance
End
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19. Example 6
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 =(2.5/100) * amount.
Zakat is not calculated if the amount is less than S.R
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20. Solution Input amount. Processing
Check if amount is below 1000  Zakat =0.
Check if amount is above 1000 Zakat =(2.5/100) * amount
Output
Zakat
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21. Solution no Start Read amount yes Amount > 1000 Zakat =0.
Zakat =(2.5/100)*amount
Print Zakat
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End