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Lecture Notes in Computer Science 2409 Edited by G Lecture Notes in Computer Science 2409 Edited by G. Goos, J. Hartmanis, and J. van Leeuwen 3 Berlin Heidelberg New York Barcelona Hong Kong London Milan Paris Tokyo David M. Mount Clifford Stein (Eds.) Algorithm Engineering and Experiments 4th International Workshop, ALENEX 2002 San Francisco, CA, USA, January 4-5, 2002 Revised Papers 13 Series Editors Gerhard Goos, Karlsruhe University, Germany Juris Hartmanis, Cornell University, NY, USA Jan van Leeuwen, Utrecht University, The Netherlands Volume Editors David M. Mount University of Maryland, Department of Computer Science College Park, MD 20742, USA E-mail: [email protected] Clifford Stein Columbia University, Department of IEOR 500W. 120 St., MC 4704 New York, NY 10027, USA E-mail: [email protected] Cataloging-in-Publication Data applied for Die Deutsche Bibliothek - CIP-Einheitsaufnahme Algorithm engineering and experimentation : 4th international workshop ; revised papers / ALENEX 2002, San Francisco, CA, USA, January4-5,2002. David M. Mount ; Clifford Stein (ed.). - Berlin ; Heidelberg ; New York ; Barcelona ; Hong Kong ; London ; Milan ; Paris ; Tokyo : Springer, 2002 (Lecture notes in computer science ; Vol. 2409) ISBN 3-540-43977-3 CR Subject Classification (1998): F.2, E.1, I.3.5, G.2 ISSN 0302-9743 ISBN 3-540-43977-3 Springer-Verlag Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. Springer-Verlag Berlin Heidelberg New York, a member of BertelsmannSpringer Science+Business Media GmbH http://www.springer.de © Springer-Verlag Berlin Heidelberg 2002 Printed in Germany Typesetting: Camera-ready by author, data conversion by PTP-Berlin, Stefan Sossna e.K. Printed on acid-free paper SPIN: 10873691 06/3142 543210 Preface The annual workshop on Algorithm Engineering and Experiments (ALENEX) provides a forum for the presentation of original research in the implementation and experimental evaluation of algorithms and data structures. ALENEX 2002 was the fourth workshop in this series. It was held in San Francisco, California on January 4–5, 2002. This volume collects extended versions of the 15 papers that were selected for presentation from a pool of 34 submissions. We would like to thank the sponsors, authors, and reviewers who helped make ALENEX 2002 a success. We also want to thank the invited speakers, Cynthia Phillips of Sandia National Laboratories, Martin Farach-Colton of Google, and Michael Kass of Pixar. Finally, we would like to thank Springer-Verlag for pu- blishing these papers in their Lecture Notes in Computer Science series. May 2002 David M. Mount Clifford Stein ALENEX 2002 Sponsors The following organizations provided direct financial support, which enabled us to host invited speakers and provide reduced registration fees for students. • Sandia National Laboratories • Akami Technologies Inc. • NEC Research The following provided in-kind support, facilitating the workshop. • SIAM, the Society for Industrial and Applied Mathematics • SIGACT, the ACM SIG on Algorithms and Computation Theory • Columbia University ALENEX 2002 Program Committee Nancy Amato (Texas A&M University) Marshall Bern (Xerox PC) Michael Goodrich (University of California, Irvine) Tom McCormick (University of British Columbia) Michael Mitzenmacher (Harvard University) David Mount (University of Maryland; Co-chair) Giri Narasimhan (Florida International University) Rajeev Raman (University of Leicester) Clifford Stein (Columbia University; Co-chair) VI ALENEX 2002 ALENEX 2002 Steering Committee Michael Goodrich (University of California, Irvine) Adam Buchsbaum (AT&T Labs) Roberto Battiti (University of Trento, Italy) Andrew V. Goldberg (Intertrust ST Lab) Michael T. Goodrich (University of California, Irvine) David S. Johnson (AT&T Bell Laboratories) Catherine C. McGeoch (Amherst College) Bernard M.E. Moret (University of New Mexico; chair) Jack Snoeyink (UNC-Chapel Hill) Table of Contents ALENEX 2002 On the Implementation of MST-Based Heuristics for the Steiner Problem in Graphs ......................................................... 1 M. Poggi de Arag˜ao,R.F. Werneck (Catholic University of Rio de Janeiro) A Time-Sensitive System for Black-Box Combinatorial Optimization ..... 16 V. Phan, P. Sumazin, S. Skiena (SUNY Stony Brook) A Compressed Breadth-First Search for Satisfiability ................... 29 D.B. Motter, I.L. Markov (University of Michigan) Using Multi-level Graphs for Timetable Information in Railway Systems .. 43 F. Schulz, D. Wagner (University of Konstanz), C. Zaroliagis (University of Patras) Evaluating the Local Ratio Algorithm for Dynamic Storage Allocation ... 60 K. Pruhs (University of Pittsburgh), E. Wiewiora (University of California, San Diego) An Experimental Study of Prefetching and Caching Algorithms for the World Wide Web .................................................. 71 M. Curcio, S. Leonardi, A. Vitaletti (Universit`adi Roma “La Sapienza”) The Treewidth of Java Programs ..................................... 86 J. Gustedt (LORIA & INRIA Lorraine), O.A. Mæhle, J.A. Telle (University of Bergen) Partitioning Planar Graphs with Costs and Weights .................... 98 L. Aleksandrov (Bulgarian Academy of Sciences, Carleton University), H. Djidjev (University of Warwick), H. Guo, A. Maheshwari (Carleton University) Maintaining Dynamic Minimum Spanning Trees: An Experimental Study . 111 G. Cattaneo, P. Faruolo, U.F. Petrillo (Universit`adi Salerno), G.F. Italiano (Universit`a di Roma “Tor Vergata”) Experimental Evaluation of a New Shortest Path Algorithm ............126 S. Pettie, V. Ramachandran, S. Sridhar (University of Texas at Austin) Getting More from Out-of-Core Columnsort ...........................143 G. Chaudhry, T. Cormen (Dartmouth College) VIII Table of Contents Topological Sweep in Degenerate Cases ...............................5 E. Rafalin, D. Souvaineufts University), I. Streinu (Smith College) Acceleration of K-Means and Related Clustering Algorithms.............166 S.J. Phillips (AT&T Labs-Research) STAR-Tree: An Efficient Self-Adjusting Index for Moving Objects .......178 C.M. Procopiuc (AT&T Research Lab), P.K. Agarwal (Duke University), S. Har-Peled (University of Illinois) An Improvement on Tree Selection Sort ...............................194 J. Chen (Bell Labs Research, Beijing) Author Index ....................................................207 On the Implementation of MST-Based Heuristics for the Steiner Problem in Graphs Marcus Poggi de Arag˜aoand Renato F. Werneck Department of Informatics, Catholic University of Rio de Janeiro, R. Marquˆesde S˜ao Vicente, 225, Rio de Janeiro, RJ, 22453-900, Brazil. [email protected], [email protected] Abstract. Some of the most widely used constructive heuristics for the Steiner Problem in Graphs are based on algorithms for the Minimum Spanning Tree problem. In this paper, we examine efficient implemen- tations of heuristics based on the classic algorithms by Prim, Kruskal, and Bor˚uvka. An extensive experimental study indicates that the the- oretical worst-case complexity of the algorithms give little information about their behavior in practice. Careful implementation improves aver- age computation times not only significantly, but asymptotically. Run- ning times for our implementations are within a small constant factor from that of Pris algorithm for the Minimum Spanning Tree problem, suggesting that there is little room for improvement. 1 Introduction The Steiner Problem in Graphs (SPG) can be stated as follows: given an undi- rected graph G =(V,E), a set ofterminals T ⊆ V , and a positive cost function c(v, w) for all (v, w) ∈ E, find a minimum weight connected subgraph of G con- taining all vertices in T . This is one ofthe most studied NP-hard problems. A wealth oflinks to recent papers on this subject can be foundin [5]. In this paper, we are especially interested in constructive heuristics, algo- rithms that build feasible solutions from scratch. They can be used as stand-alone algorithms, providing solutions ofreasonable quality within a short amount of time. However, their application is much broader. They are often used as sub- routines ofmore elaborate primal heuristics [2,10], dual heuristics [8], and exact algorithms [4,8]. Regardless ofthe application, constructive heuristics should be as fast as possible, while preserving solution quality. A number ofsuch heuristics are described in the literature (see [3,12] for surveys). We focus our attention on heuristics that are direct extensions of exact algorithms for the Minimum Spanning Tree (MST) problem. The main contribu- tion of this paper are new, fast implementations for these methods. This includes not only versions ofthe traditional methods based on Pris and Kruskas al- gorithms, but also a Bor˚uvka-based heuristic, a natural extension that has not Current addres Department of Computer Science, Princeton University, Princeton, NJ, 08544. D. Mount and C. Stein (Eds.): ALENEX 2002, LNCS 2409, pp. 1–15, 2002. c Springer-Verlag Berlin Heidelberg 2002 2 M. Poggi
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