What Is Huffman in Data Structure?
In data structure, Huffman coding is a popular algorithm used for data compression. It was developed by David A. Huffman in 1952 while he was a Ph.D. student at MIT. Huffman coding is widely used in various applications, including file compression, image compression, and data transmission.
Huffman Algorithm
The Huffman algorithm works by assigning variable-length codes to different characters based on their frequency of occurrence in the input data. This means that more frequently occurring characters are assigned shorter codes, while less frequently occurring characters are assigned longer codes.
The algorithm uses a binary tree to represent the codes. The tree is built in a bottom-up manner starting with individual nodes for each character and combining them until a single root node is reached.
Steps to Build the Huffman Tree:
- Create a leaf node for each character and assign their frequencies.
- Sort all the leaf nodes based on their frequencies.
- Take the two nodes with the lowest frequencies and create an internal node as their parent. Assign the sum of their frequencies as the frequency of the internal node.
- Repeat step 3 until there is only one node left, which becomes the root of the Huffman tree.
Once the Huffman tree is constructed, each character can be represented by its corresponding code obtained by traversing from the root to that character’s leaf node. The left child represents a ‘0’ bit, and the right child represents a ‘1’ bit.
Huffman Compression
Huffman coding achieves data compression by representing frequently occurring characters with shorter codes and less frequently occurring characters with longer codes. This results in reducing the overall size of the data.
When compressing a file using Huffman coding, the first step is to build the Huffman tree based on the frequency of characters in the file. Then, each character in the file is replaced with its corresponding Huffman code. The compressed file is generated by concatenating these codes.
Huffman Decompression
To decompress a file compressed using Huffman coding, the compressed file and the corresponding Huffman tree are required. The decompression process involves traversing the Huffman tree based on the bits in the compressed file and reconstructing the original characters.
By using Huffman coding for compression and decompression, it is possible to achieve lossless data compression, where no information is lost during compression and decompression.
Conclusion
Huffman coding is an efficient algorithm for data compression that assigns variable-length codes to characters based on their frequency of occurrence. It reduces the overall size of data by representing frequently occurring characters with shorter codes. Understanding how Huffman coding works can be beneficial for applications involving data compression and transmission.