Lecture Notes in Computer Science 8496

Transcription

1 Lecture Notes in Computer Science 8496 Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M. Kleinberg Cornell University, Ithaca, NY, USA Alfred Kobsa University of California, Irvine, CA, USA Friedemann Mattern ETH Zurich, Switzerland John C. Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen TU Dortmund University, Germany Demetri Terzopoulos University of California, Los Angeles, CA, USA Doug Tygar University of California, Berkeley, CA, USA Gerhard Weikum Max Planck Institute for Informatics, Saarbruecken, Germany

2 Alfredo Ferro Fabrizio Luccio Peter Widmayer (Eds.) Fun with Algorithms 7th International Conference, FUN 2014 Lipari Island, Sicily, Italy, July 1-3, 2014 Proceedings 13

3 Volume Editors Alfredo Ferro Università degli Studi di Catania Dipartimento di Matematica e Informatica, Viale A. Doria 6, Catania, Italy ferro@dmi.unict.it Fabrizio Luccio Università di Pisa, Dipartimento di Informatica Largo B. Pontecorvo 3, Pisa, Italy luccio@di.unipi.it Peter Widmayer ETH Zürich, Institute of Theoretical Computer Science Universitätsstrasse 6, 8092 Zürich, Switzerland widmayer@inf.ethz.ch ISSN e-issn ISBN e-isbn DOI / Springer Cham Heidelberg New York Dordrecht London Library of Congress Control Number: LNCS Sublibrary: SL 1 Theoretical Computer Science and General Issues Springer International Publishing Switzerland 2014 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher s location, in ist current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Typesetting: Camera-ready by author, data conversion by Scientific Publishing Services, Chennai, India Printed on acid-free paper Springer is part of Springer Science+Business Media (

4 Preface FUN with Algorithms is dedicated to the use, design, and analysis of algorithms and data structures, focusing on results that provide amusing, witty but nonetheless original and scientifically profound contributions to the area. Donald Knuth s famous quote captures this spirit nicely:... pleasure has probably been the main goal all along. But I hesitate to admit it, because computer scientists want to maintain their image as hard-working individuals who deserve high salaries. Sooner or later society will realise that certain kinds of hard work are in fact admirable even though they are more fun than just about anything else. The previous FUNs were held in Elba Island, Italy; in Castiglioncello, Tuscany, Italy; in Ischia Island, Italy; and in San Servolo Island, Venice, Italy. Special issues of Theoretical Computer Science, Discrete Applied Mathematics, andtheory of Computing Systems were dedicated to them. This volume contains the papers presented at the 7th International Conference on Fun with Algorithms 2014 that was held during July 1 3, 2014, on Lipari Island, Italy. The call for papers attracted 49 submissions from all over the world, addressing a wide variety of topics, including algorithmic questions rooted in biology, cryptography, game theory, graphs, the Internet, robotics and mobility, combinatorics, geometry, stringology, as well as space-conscious, randomized, parallel, distributed algorithms, and their visualization. Each submission was reviewed by three Program Committee members. After a careful reviewing process and a thorough discussion, the committee decided to accept 29 papers. In addition, the program featured two invited talks by Paolo Boldi and Erik Demaine. Extended versions of selected papers will appear in a special issue of the journal Theoretical Computer Science. We thank all authors who submitted their work to FUN 2014, all Program Committee members for their expert assessments and the ensuing discussions, all external reviewers for their kind help, and Alfredo Ferro, Rosalba Giugno, Alfredo Pulvirenti as well as Giuseppe Prencipe for the organization of the conference and everything around it. We used EasyChair ( throughout the entire preparation of the conference, for handling submissions, reviews, the selection of papers, and the production of this volume. It greatly facilitated the whole process. We want to warmly thank the people who designed it and those who maintain it. Warm thanks also go to Alfred Hofmann and Ingrid Haas at

5 VI Preface Springer with whom collaborating was a pleasure. We gratefully acknowledge financial support by the Department of Computer Science of ETH Zurich, and the patronage of the European Association for Theoretical Computer Science (EATCS). April 2014 Alfredo Ferro Fabrizio Luccio Peter Widmayer

6 Organization Program Committee Jérémie Chalopin Pierluigi Crescenzi Shantanu Das Josep Diaz Yann Disser Paolo Ferragina Fedor Fomin Pierre Fraigniaud Leszek Gasieniec Fabrizio Grandoni Evangelos Kranakis Danny Krizanc Flaminia Luccio Matus Mihalak Linda Pagli David Peleg Paolo Penna Giuseppe Persiano Giuseppe Prencipe Jose Rolim Piotr Sankowski Ryuhei Uehara Jorge Urrutia Peter Widmayer Christos Zaroliagis LIF, CNRS, Aix Marseille Université, France Florence University, Italy Aix-Marseille Université, France UPC Barcelona, Spain TU Berlin, Germany University of Pisa, Italy University of Bergen, Norway Université Paris Diderot, France University of Liverpool, UK IDSIA, University of Lugano, Switzerland Carleton University, Canada Wesleyan University, USA Ca Foscari University of Venice, Italy ETH Zurich, Switzerland University of Pisa, Italy The Weizmann Institute, Israel Università disalerno,italy UniversitàdiSalerno,Italy University of Pisa, Italy University of Geneva, Switzerland University of Warsaw, Poland Japan Advanced Institute of Science and Technology Universidad Nacional Autónoma de México ETH Zurich, Switzerland Computer Technology Institute, University of Patras, Greece Additional Reviewers Bernasconi, Anna Bonnet, Edouard Borassi, Michele Cicalese, Ferdinando Couëtoux, Basile De Prisco, Roberto Di Luna, Giuseppe Antonio Donati, Beatrice Drange, Paal Groenaas Ferraioli, Diodato Focardi, Riccardo Fotakis, Dimitris Gallopoulos, Efstratios Giotis, Ioannis

7 VIII Organization Kontogiannis, Spyros Labourel, Arnaud Luccio, Fabrizio Mamageishvili, Akaki Marino, Andrea Naves, Guyslain Pallottino, Lucia Pisanti, Nadia Poupet, Victor Rossi, Gianluca Ruj, Sushmita Sacomoto, Gustavo Serna, Maria Squarcina, Marco Uznanski, Przemyslaw Venturini, Rossano

8 Table of Contents Algorithmic Gems in the Data Miner s Cave... 1 Paolo Boldi Fun with Fonts: Algorithmic Typography Erik D. Demaine and Martin L. Demaine Happy Edges: Threshold-Coloring of Regular Lattices Muhammad Jawaherul Alam, Stephen G. Kobourov, Sergey Pupyrev, and Jackson Toeniskoetter Classic Nintendo Games Are (Computationally) Hard Greg Aloupis, Erik D. Demaine, Alan Guo, and Giovanni Viglietta On the Solvability of the Six Degrees of Kevin Bacon Game - A Faster Graph Diameter and Radius Computation Method Michele Borassi, Pierluigi Crescenzi, Michel Habib, Walter Kosters, Andrea Marino, and Frank Takes No Easy Puzzles: A Hardness Result for Jigsaw Puzzles Michael Brand Normal, Abby Normal, Prefix Normal Péter Burcsi, Gabriele Fici, Zsuzsanna Lipták, Frank Ruskey, and Joe Sawada Nonconvex Cases for Carpenter s Rulers Ke Chen and Adrian Dumitrescu How to Go Viral: Cheaply and Quickly Ferdinando Cicalese, Gennaro Cordasco, Luisa Gargano, Martin Milanič, Joseph G. Peters, and Ugo Vaccaro Synchronized Dancing of Oblivious Chameleons Shantanu Das, Paola Flocchini, Giuseppe Prencipe, and Nicola Santoro Another Look at the Shoelace TSP: The Case of Very Old Shoes Vladimir G. Deineko and Gerhard J. Woeginger Playing Dominoes Is Hard, Except by Yourself Erik D. Demaine, Fermi Ma, and Erik Waingarten

9 X Table of Contents UNO Gets Easier for a Single Player Palash Dey, Prachi Goyal, and Neeldhara Misra Secure Auctions without Cryptography Jannik Dreier, Hugo Jonker, and Pascal Lafourcade Towards an Algorithmic Guide to Spiral Galaxies Guillaume Fertin, Shahrad Jamshidi, and Christian Komusiewicz Competitive Analysis of the Windfall Game Rudolf Fleischer and Tao Zhang Excuse Me! or The Courteous Theatregoers Problem (Extended Abstract) Konstantinos Georgiou, Evangelos Kranakis, and Danny Krizanc Zombie Swarms: An Investigation on the Behaviour of Your Undead Relatives Vincenzo Gervasi, Giuseppe Prencipe, and Valerio Volpi Approximability of Latin Square Completion-Type Puzzles Kazuya Haraguchi and Hirotaka Ono Sankaku-Tori: An Old Western-Japanese Game Played on a Point Set Takashi Horiyama, Masashi Kiyomi, Yoshio Okamoto, Ryuhei Uehara, Takeaki Uno, Yushi Uno, and Yukiko Yamauchi Quell Minghui Jiang, Pedro J. Tejada, and Haitao Wang How Even Tiny Influence Can Have a Big Impact! Barbara Keller, David Peleg, and Roger Wattenhofer Optimizing Airspace Closure with Respect to Politicians Egos Irina Kostitsyna, Maarten Löffler, and Valentin Polishchuk Being Negative Makes Life NP-hard (for Product Sellers) Sven O. Krumke, Florian D. Schwahn, and Clemens Thielen Clearing Connections by Few Agents Christos Levcopoulos, Andrzej Lingas, Bengt J. Nilsson, and Pawe l Żyliński Counting Houses of Pareto Optimal Matchings in the House Allocation Problem Andrei Asinowski, Balázs Keszegh, and Tillmann Miltzow Practical Card-Based Cryptography Takaaki Mizuki and Hiroki Shizuya

10 Table of Contents XI The Harassed Waitress Problem Harrah Essed and Wei Therese Lemmings Is PSPACE-Complete Giovanni Viglietta Finding Centers and Medians of a Tree by Distance Queries Bang Ye Wu Swapping Labeled Tokens on Graphs Katsuhisa Yamanaka, Erik D. Demaine, Takehiro Ito, Jun Kawahara, Masashi Kiyomi, Yoshio Okamoto, Toshiki Saitoh, Akira Suzuki, Kei Uchizawa, and Takeaki Uno Author Index