On-line construction of position heaps

Abstract

We propose a simple linear-time on-line algorithm for constructing a position heap for a string (Ehrenfeucht et al., 2011 [8]). Our definition of position heap differs slightly from the one proposed in Ehrenfeucht et al. (2011) [8] in that it considers the suffixes ordered in the descending order of length. Our construction is based on classic suffix pointers and resembles Ukkonen@?s algorithm for suffix trees (Ukkonen, 1995 [17]). Using suffix pointers, the position heap can be extended into the augmented position heap that allows for a linear-time string matching algorithm (Ehrenfeucht et al., 2011 [8]).