🗜️ Huffman File Compressor (C++)

A complete lossless file compression and decompression tool implemented in C++ using the Huffman Coding algorithm.

This project compresses a text file into a compact binary format and reconstructs the original file without any data loss.

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🚀 Features

• Lossless compression using Huffman Coding
• Binary bit-level encoding (real compression, not 0/1 text)
• Automatic decompression
• Stores frequency table inside file header
• Rebuilds exact Huffman Tree during decoding
• Handles padding bits safely
• CLI based menu system

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🧠 How It Works

Compression

1. Read input file

2. Count character frequencies

3. Build Huffman Tree (Min Heap + Greedy algorithm)

4. Generate binary codes

5. Pack bits into bytes

6. Store:

   • Original file size
   • Frequency table
   • Encoded binary data

Decompression

1. Read header (size + frequency table)
2. Rebuild identical Huffman tree
3. Read binary bits
4. Traverse tree
5. Restore original text

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📂 Project Structure

Huffman-File-Compressor/
│
├── include/
│   ├── HuffmanNode.h
│   ├── HuffmanTree.h
│   ├── Compressor.h
│   └── Decompressor.h
│
├── src/
│   ├── HuffmanTree.cpp
│   ├── Compressor.cpp
│   └── Decompressor.cpp
│
├── input/
│   └── test.txt
│
├── output/
│   ├── compressed.bin
│   └── decompressed.txt
│
├── build/
│
└── main.cpp

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⚙️ Compilation & Run

Compile

g++ src/*.cpp main.cpp -o build/app

Run

build/app

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▶️ Menu

1 → Compress File
2 → Decompress File
3 → Exit

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📊 Example

Input:

hello huffman compression project
this is my first compressor

Compressed → compressed.bin Decompressed → decompressed.txt (identical to input)

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🧩 Concepts Used

• Greedy Algorithms
• Priority Queue (Min Heap)
• Binary Trees
• Bit Manipulation
• File Handling (Binary I/O)
• Object Oriented Programming
• Data Structures & Algorithms

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🎯 Learning Outcomes

This project demonstrates understanding of:

• Real file compression
• Memory-efficient encoding
• Serialization & deserialization
• Tree reconstruction
• Practical DSA implementation

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📜 License

Open for learning and educational use.