Problem Solving using Computer

Programming is not just about writing syntax; it's about solving problems logically. Before touching the keyboard, we must define the strategy.

2.1 The Problem-Solving Life Cycle

1. Requirement Analysis: Understand what the problem is.
2. Algorithm Design: Plan the step-by-step solution.
3. Flowcharting: Visualize the logic.
4. Coding: Translate the logic into a programming language.
5. Testing & Debugging: Find and fix errors.

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2.2 Algorithms

An algorithm is a finite set of step-by-step instructions to solve a specific problem.

Characteristics of a Good Algorithm:

• Input: It should have zero or more inputs.
• Output: It must produce at least one output.
• Definiteness: Each step must be clear and unambiguous.
• Finiteness: It must stop after a finite number of steps.
• Effectiveness: Steps must be basic enough to be performed.

Example Algorithm: Add two numbers

1. START
2. Declare variables A, B, and SUM.
3. Read values for A and B.
4. Add A and B and store the result in SUM (SUM = A + B).
5. Display SUM.
6. STOP

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2.3 Flowcharts

A flowchart is a graphical representation of an algorithm.

Standard Flowchart Symbols:

Symbol	Name	Description
	Terminal	Start or End of the program.
	Input/Output	Used for reading or writing data.
	Process	Arithmetic operations and data manipulation.
	Decision	Used for conditions (True/False).

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2.4 Pseudocode

Pseudocode (False Code) is an informal way of writing an algorithm using plain English mixed with programming logic markers like IF, THEN, ELSE, WHILE.

Example Pseudocode: Check if a number is Even or Odd

BEGIN
    READ number
    IF number % 2 == 0 THEN
        PRINT "Number is Even"
    ELSE
        PRINT "Number is Odd"
    ENDIF
END

Refer to the Lecture Slides for visual examples of complex flowcharts.