Question

The Huffman coding algorithm used for data compression is based on which algorithmic strategy?

• A. Divide and Conquer
• B. Dynamic Programming
• C. Backtracking
• D. Greedy Method

Hint:

While many greedy algorithms don't always yield the best global solution (like the Change-Making problem), Huffman coding is mathematically proven to produce an optimal prefix code for a given set of frequencies.

Answer 1

The Correct Option is D

Concept: Huffman coding is a popular algorithm used for lossless data compression. It assigns variable-length codes to input characters, with shorter codes assigned to more frequent characters.
• Greedy Strategy: An algorithmic paradigm that builds up a solution piece by piece, always choosing the next piece that offers the most obvious and immediate benefit.
• Optimal Prefix Code: No code is a prefix of another, ensuring unique decodability.

Step 1: Understanding the Huffman construction process.
The algorithm works by creating a binary tree of nodes. It starts with a list of all characters and their frequencies. In each step, it selects the two nodes with the lowest frequencies.

Step 2: Identifying the greedy choice.
By always picking the two smallest frequencies to merge into a new internal node, the algorithm is making a "locally optimal" choice. It assumes that combining the least frequent items now will lead to an globally optimal tree (the shortest average code length) later.

Step 3: Conclusion.
Since the algorithm makes the best possible choice at each local stage without reconsidering previous choices, it is a classic implementation of the Greedy Method.