# A Parallel Priority Queue with Constant Time Operations

Technical Report, MPI-I-97-1-011, Max-Planck-Institut für Informatik, 19 pages, May 1997.

## Abstract

We present a parallel priority queue that supports the following
operations in constant time: * parallel insertion * of a sequence of
elements ordered according to key,
* parallel decrease key * for a sequence of elements ordered
according to key, * deletion of the minimum key element*,
as well as * deletion of an arbitrary element*. Our data structure is
the first to
support multi insertion and multi decrease key in constant time. The
priority queue can be implemented on the EREW PRAM, and can perform any
sequence of *n* operations in *O*(*n*) time and *O*(*m*log *n*) work,
*m* being the total number of keys inserted and/or updated. A main
application is a parallel implementation of Dijkstra's algorithm for the
single-source shortest path problem, which runs in *O*(*n*) time and
*O*(*m*log *n*) work on a CREW PRAM on graphs with *n* vertices and *m*
edges. This is a logarithmic factor improvement in the running time
compared with previous approaches.

**Online version**
mpi-i-97-1-011.pdf (272 Kb)

**BIBT**_{E}X entry

@techreport{mpi-i-97-1-011,
address = "Im Stadtwald, D-66123 Saarbr{\"u}cken, Germany",
author = "Gerth St{\o}lting Brodal and Jesper Larsson Tr{\"a}ff and Christos D. Zaroliagis",
institution = "Max-Planck-Institut f{\"u}r Informatik",
month = "May",
number = "MPI-I-97-1-011",
pages = "19",
title = "A Parallel Priority Queue with Constant Time Operations",
year = "1997"
}