In-Place Update of Suffix Array While Recoding Words

Abstract

Motivated by grammatical inference and data compression applications, we propose an algorithm to update a suffix array while in the indexed text some occurrences of a given word are substituted by a new character. Compared to other published index update methods, the problem addressed here may require the modification of a large number of distinct positions over the original text. The proposed algorithm uses the specific internal order of suffix arrays in order to update simultaneously groups of indices, and ensures that only indices to be modified are visited. Experiments confirm a significant execution time speedup compared to the construction of suffix array from scratch at each step of the application.

A Fast Algorithm for the Largest Area First Parsing of Real Strings

“…Unfortunately, this does not seem to be the case with LAF parsing since a method for an efficient (amortized constant time) global suffix tree update (of all occurrences of a substring) is not known. Standard suffix arrays are even harder to update because they require the reordering of a contiguous array [20], [21].…”