Truncated Suffix Trees and their Applications to Data Compression

The suffix tree is a fundamental data structure in the area of string algorithms and it has been used in many applications including data compression. In this paper we propose a data structure called the truncated suffix tree, which is a truncated version of the suffix tree. We also present two linear-time construction algorithms for truncated suffix trees and two algorithms that delete suffixes from truncated suffix trees.The truncated suffix tree is particularly a useful data structure for LZ77 that compresses using a sliding window of a fixed size. Our algorithms lead to two implementations of LZ77 that maintain sliding windows by truncated suffix trees. We also present a technique of finding the longest match in a sliding window, which is a crucial step in LZ77.