[FEATURE REQUEST] Add LZ77 and LZ78 Algorithms to Compression Package

[Microindole]

What would you like to Propose?

I would like to propose adding implementations for the following fundamental lossless compression algorithms to the compression category:

1. LZ77 (Lempel–Ziv 77)
2. LZ78 (Lempel–Ziv 78)

Adding these algorithms would significantly enhance the collection of classic compression techniques, complementing the existing LZW and Run-Length Encoding algorithms within the package. LZ77 and LZ78 represent key variations in dictionary-based compression and are foundational to many modern compression schemes (like DEFLATE used in gzip and PNG).

Issue details

Algorithm 1: LZ77 (Lempel–Ziv 77)

• Problem Statement: LZ77 is a lossless data compression algorithm that achieves compression by replacing repeated occurrences of data with references to a single copy of that data existing earlier in the uncompressed data stream (using a sliding window). A match is encoded by a pair of numbers: a distance (offset back in the window) and a length.
• Example (Conceptual):
  • Input: "ababcabc"
  • Output: A sequence representing encoded data, often as tuples like (offset, length, next_character). The exact output format can vary, but conceptually for this input, it might look something like: (0,0,'a'), (0,0,'b'), (2,2,'c'), (3,3,'<End Marker>') (representing 'a', 'b', then 'ab' found 2 back, followed by 'c', then 'abc' found 3 back).
• Proposed File Path: src/main/java/com/thealgorithms/compression/LZ77.java

Algorithm 2: LZ78 (Lempel–Ziv 78)

• Problem Statement: LZ78 is a dictionary-based lossless data compression algorithm. It processes input data sequentially, building a dictionary of phrases encountered so far. It outputs pairs, typically (dictionary_index, next_character), where the index refers to the longest matching phrase already in the dictionary.
• Example (Conceptual):
  • Input: "ABAABABAABAB"
  • Output: A sequence representing encoded data, often as pairs like (index, character). For this input, a possible output sequence could be: (0,'A'), (0,'B'), (1,'A'), (2,'B'), (4,'A'), (5,'B'). (This implicitly builds a dictionary like: 1:A, 2:B, 3:AA, 4:BA, 5:ABA, 6:BAB).
• Proposed File Path: src/main/java/com/thealgorithms/compression/LZ78.java

Additional Information

No response