Klase Notes

Read and Learn

Criteria for an Algorithm

• Input – There is data that needs to be processed.
• Output – There is a result or report produced.
• Definiteness – Instructions must be clear and free from ambiguity.
• Finiteness – The algorithm must end after a definite number of steps.
• Effectiveness – Steps must be simple and practical to perform.

Pseudocode

Flowchart

Definitions of Flowchart

• "Use of symbols and phrases to designate the logic of how a problem is solved."
• "A method for defining logical program steps using symbols representing Input, Process, and Output."
• "A two-dimensional representation of an algorithm using standard symbols."
• "A diagram showing the order in which procedures are carried out; it serves as the blueprint of the program."

Basic Symbols Used in Flowcharting

Example: Simple Payroll System

A simple payroll system computes the total salary of an employee using different modules.

1. Read Module

1. Read Hours and PayRate
2. Exit

Read Hours, PayRate
Exit

2. Calculation Module

1. Compute Gross Pay
2. Exit

GrossPay = Hours * PayRate
Exit

3. Print Module

1. Print Pay
2. Exit

Print Pay
Exit

Logic Structures

Programs are built using three main logic structures.

1. Sequence

Processes are executed step-by-step in order.

1. Read value of N
2. Print value of N
3. End

Read N
Print N
End

2. Selection (IF – THEN – ELSE)

This structure allows the program to choose between alternatives.

Bonus = 0
Read EmployeeName, Salary

If Salary < 2000
    Bonus = Salary * 0.50
Else
    Bonus = 1500

Print EmployeeName, Bonus
End

3. Repetition (Loop)

This structure repeats a process while a condition remains true.

Counter = 1

While Counter <= 10
    Print Counter
    Counter = Counter + 1
End While

Quiz #5

1. Algorithm
2. Flowchart
3. Pseudocode
4. Program

5. Criteria for Algorithm

6. Six Steps in Problem Solving

Activity 5

1. Create a flowchart that accepts three numbers and displays the highest and lowest.
2. Draw a flowchart to determine if a voter is qualified (Age ≥ 18).
3. Create a flowchart that converts hours to minutes. (1 hour = 60 minutes)
4. Draw a flowchart that checks if a user is authorized. Password = pass.
5. Create a flowchart that computes the sum of three numbers.
6. Construct a flowchart that accepts 10 numbers and displays positive and negative numbers.
7. Create a flowchart that swaps the values of two numbers A and B.

References

• Workbook in C Programming – Gatpandan & Rollan
• Kernighan & Ritchie – The C Programming Language
• Schildt – Turbo C/C++ The Complete Reference
• Sellapan – C++ Through Examples
• Uckan – Problem Solving Using C
• www.cprogramming.com
• www.cplusplus.com
• www.tutorialspoint.com