C++ Huffman Coding

This project implements Huffman coding for lossless data compression and decompression in C++.
It includes building a Huffman tree, compressing input text into binary code, serializing the tree, and reconstructing the tree to decompress back to the original text.

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✨ Features

• Count character frequencies and build a min-heap priority queue
• Construct a Huffman tree using a custom HeapQueue
• Generate prefix codes for each character
• Compress input strings into binary representation
• Serialize the Huffman tree into a compact string
• Reconstruct the tree and decompress encoded strings
• Includes unit tests with Catch2 across multiple large test cases

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📂 Project Structure

├── HeapQueue.hpp # Custom heap-based priority queue

├── HuffmanBase.hpp # Abstract base class for Huffman coding

├── HuffmanBase.cpp # Node implementation details

├── HuffmanTree.hpp # Huffman tree implementation

├── HuffmanTree.cpp # Compression, serialization, decompression

├── TestStrings.hpp # Large test input strings and expected outputs

├── PP3Test.cpp # Unit tests using Catch2

├── catch.hpp # Catch2 single-header test framework

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🧪 Testing

The project uses Catch2 for unit testing.

Compile and run tests

g++ -std=c++17 -Wall *.cpp -o huffman
./huffman -s

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🖥️ Expected output

All tests passed (12 assertions in 1 test case)

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🎯 Learning Outcomes

• Applied data compression techniques using Huffman coding

• Gained experience with trees, heaps, and priority queues

• Practiced recursive algorithms (tree traversal, serialization)

• Implemented and validated using automated unit tests

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📜 Authors

Daud Ahmad Nisar

Computer Science Student at the University of South Florida

daudnisar1@gmail.com