Objective:

By the end of this lesson, students will be able to:

• Define an algorithm and explain its importance in IT.
• Differentiate between flowcharts and pseudocode
• Create a basic flowchart and write corresponding pseudocode.
• Identify and apply control structures: sequence, selection, and iteration.
• Solve real-life problems using algorithms.

• An algorithm is a step-by-step procedure or set of instructions designed to perform a task or solve a problem.
• An algorithm can be written in different ways, including natural language, flowcharts, pseudocode, and actual programming code.

Importance of Algorithms in IT

• Algorithms form the backbone of computer programming and software development.
• They help in solving complex problems efficiently and optimize system performance.
• Examples of algorithm applications:
  • Google’s search engine uses algorithms to fetch the most relevant results.
  • Social media platforms use recommendation algorithms for personalized content.
  • GPS applications use algorithms to find the shortest route.

Flowcharts

A flowchart is a visual representation of an algorithm using symbols to depict different types of operations.

Flowchart Symbols and Their Meanings:

• Oval (Terminator): Represents Start or End of the algorithm.
• Rectangle (Process): Represents instructions or actions to be performed.
• Parallelogram (Input/Output): Represents input (user input) and output (display results).
• Diamond (Decision): Represents decision-making steps (yes/no, true/false).
• Arrows: Show the flow of operations in the algorithm.

Pseudocode

• Pseudocode is a high-level, plain-language representation of an algorithm that follows programming logic but does not use strict syntax like actual code.
• It bridges the gap between an algorithm and real programming languages.

Pseudocode Conventions:

• Use INPUT and OUTPUT to indicate data entry and result display.
• Use IF, ELSE, WHILE, FOR to structure logic.
• Indentation helps improve readability.

Compare the pseudocode with the flowchart.

Control Structures

Control structures determine how statements are executed in an algorithm.

• Sequence (Linear Execution)
  • Instructions are executed one after another in a logical order.
  • Example: Making a cup of coffee

• Selection (Decision-Making)
  • Uses IF-ELSE statements to choose between different actions.
  • Example: Checking if a person is eligible to vote

• Iteration (Loops – Repetition of Steps)
  • Uses FOR, WHILE, DO-WHILE to repeat steps until a condition is met.
  • Example: Printing numbers from 1 to 5

In Summary