Faster semi-external suffix sorting

Abstract

Suffix array (SA) construction is a time-and-memory bottleneck in many string processing applications. In this paper we improve the runtime of a small-space — semi-external — SA construction algorithm by Kärkkäinen (TCS, 2007) [5]. We achieve a speedup in practice of 2–4 times, without increasing memory usage. Our main contribution is a way to implement the “pointer copying” heuristic, used in less space-efficient SA construction algorithms, in a memory-efficient way.