• Overview
• Prerequisites
• Performance Analysis
• Implementation Details
• Usage
• Testing
• Visual Comparison

This project implements and compares two multiplication algorithms:

1. Simple Multiplication Algorithm - A traditional approach with O(n²) complexity
2. Karatsuba Algorithm - A faster divide-and-conquer approach

• Java Development Kit (JDK) 8 or higher
• Basic understanding of algorithm complexity
• Familiarity with Java programming

The simple multiplication algorithm is implemented with the following steps and their time complexities:

1. Generating Random Numbers 🎲

   • Time Complexity: O(n)
   • Generates random numbers with n digits
   • Constant time operation for each digit

2. Storing Digits in Arrays 📦

   • Time Complexity: O(n)
   • Iterates once over n digits
   • Stores each digit in separate arrays

3. Performing Multiplication ✖️

   • Time Complexity: O(n²)
   • Nested loops for digit-by-digit multiplication
   • Most significant part of the algorithm

4. Handling Carries and Partial Products ➕

   • Time Complexity: O(n²)
   • Manages carries and accumulates partial products
   • Nested within multiplication loops

5. Result Output 📝

   • Time Complexity: O(n)
   • Linear iteration over result digits
   • Formats and displays the final product

Overall Time Complexity: O(n²) ⏱️

A faster multiplication algorithm that reduces the number of multiplication operations through recursive decomposition.

1. Base Case ⚡

   • If n = 1, uses simple multiplication
   • Direct multiplication for single-digit numbers

2. Recursive Decomposition 🔄

   • Splits numbers into halves (a, b) and (c, d)
   • Performs three recursive multiplications:
     • ac
     • bd
     • (a+b)(c+d)

3. Final Computation 🎯

   • Combines results using the formula:
   • ac * 10ⁿ + ((a+b)(c+d) - ac - bd) * 10ⁿ/² + bd

• Reduces multiplication operations
• More efficient for large numbers
• Recursive approach with three subproblems

• Both algorithms are implemented in Java
• Includes performance counters for operation tracking
• Supports random number generation for testing
• Validates results through assertions

.
├── SimpleMultiplication.java    # Simple multiplication implementation
├── Karatsuba.java              # Karatsuba algorithm implementation
├── Graph of Karatsuba Algorithm.xlsx    # Performance graphs
└── Graph for Simple Multiplication.xlsx # Performance graphs

1. Compile the Java files:

   javac SimpleMultiplication.java
   javac Karatsuba.java

2. Run the algorithms:

   java SimpleMultiplication
   java Karatsuba

3. Configure parameters:

   • Modify numberOfDigits in both files to change input size
   • Adjust MAX_VALUE to change number of test iterations

• Both algorithms are tested with random numbers
• Results are compared with expected values
• Includes assertion checks for accuracy
• Supports configurable number of digits and test iterations

The project includes Excel files with performance graphs:

• Graph of Karatsuba Algorithm.xlsx
• Graph for Simple Multiplication.xlsx

These graphs visualize:

• Operation count vs. input size
• Time complexity comparison
• Performance differences between algorithms

Feel free to:

• Report issues
• Suggest improvements
• Submit pull requests

This project is open source and available for educational purposes.