LCP array construction using O(Sort(n)) (or less) I/Os

Abstract

The suffix array, one of the most important data structures in modern string processing, needs to be augmented with the longestcommon- prefix (LCP) array in many applications. Their construction is often a major bottleneck especially when the data is too big for internal memory. While there are external memory algorithms that construct the suffix array and the LCP array simultaneously in the optimal I/O complexity of O(sort(n)), for several reasons it would be desirable to construct the suffix array first and then the LCP array from the suffix array in a separate stage. In this paper we describe the first algorithm that achieves O(sort(n)) I/O complexity for the LCP array construction stage and is not an extension of a suffix sorting algorithm. As a variant, we obtain a Monte Carlo algorithm that, given a sparse suffix array containing m