Suffix trays and suffix trists: Structures for faster text indexing

Suffix trees and suffix arrays are two of the most widely used data structures for text indexing. Each uses linear space and can be constructed in linear time [3,5,6,7]. However, when it comes to answering queries, the prior does so in O(m log vertical bar Sigma vertical bar) time, where m is the query size, vertical bar Sigma vertical bar is the alphabet size, and the latter does so in O(m +log n), where n is the text size. We propose a novel way of combining the two into, what we call, a suffix tray. The space and construction time remain linear and the query time improves to O(m + log vertical bar Sigma vertical bar). We also consider the online version of indexing, where the indexing structure continues to update the text online and queries are answered in tandem. Here we suggest a suffix trist, a cross between a suffix tree and a suffix list. It supports queries in O(m+log vertical bar Sigma vertical bar). The space and text update time of a suffix trist are the same as for the suffix tree or the suffix list.