Parallel Computation of the Burrows Wheeler Transform in Compact Space
José Fuentes-Sepúlveda, Gonzalo Navarro, and Yakov Nekrich
The Burrows-Wheeler Transform (BWT) has become since its introduction a key
tool for representing large text collections in compressed space while
supporting indexed searching: on a text of length n over an alphabet
of size s, it requires O(n lg s) bits of space, instead of the
O(n lg n) bits required by classical indexes. A challenge for its
adoption is to build it within O(n lg s) bits as well. There are
some sequential algorithms building it within this space, but no such a
parallel algorithm. In this paper we present a PRAM CREW algorithm to build
the BWT using O(n sqrt(lg n)) work, O(lg^3 n / lg s) depth,
and O(n lg s) bits.