DOCSLIB.ORG

Combinatorial Game Theory Workshop

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Combinatorial Game Theory Workshop Combinatorial Game Theory Workshop E. Berlekamp (Berkeley), M. Mueller (University of Alberta), R. J. Nowakowski (Dalhousie University), D. Wolfe (Gustavus Adolphus College). June 18 to June 23, 2005 A main aim of the workshop was to bring together the two camps, mathematicians working in combinatorial game theory and computer scientists interested in algorithmics and Artificial intelli- gence. The Workshop attracted a mix of people from both communities (17 from mathematics, 16 from computer science and 2 undergraduates) as well as a mixture of new and established researchers. The oldest was Richard Guy, turning 90 in 2006 and the youngest was in 3rd year University. There were attendees from Europe, Asia as well as North America. The Workshop succeeded in its primary goal and more. New collaborations were struck. There was quick dissemination and evaluation of major new results and new results were developed during the Workshop. Part of the success was due to the staff and facilities at BIRS. The facilities at BIRS were appreciated by all the participants. The main room allowed lectures to mix computer presentations with overheads and chalkboard calculations. (No prizes for guessing which community used which technology.) The coffee lounges and break away rooms allowed dis- cussions to continue on, in comfort, until late in the night. Our thanks go to all the staff who made the stay such a wonderful experience and to the BIRS organization for hosting the workshop. The elder statesmen of the community, Berlekamp, Conway, Fraenkel and Guy, all took active roles in the proceedings. The first three gave survey talks on various topics and all were involved in discussions throughout the days and the evenings. The younger (established) generation were represented by the likes of Demaine, Grossman, M¨uller and Siegel. As befits a workshop on combinatorial games, games were invented, played and analyzed. Philoso- phers Football (Phutball) was much in evidence. There was a Konane tournament played over three evenings. Much effort went into attempting an analysis of Sticky Towers of Hanoi, a game invented at the Workshop by Conway, spearheaded by Conway and the youngest attendee, Alex Fink. There were many representatives of the Go community quite a few of whom had never met each other. Collaboration is very important in this community. For example, David Wolfe presented a progress report on work of G. A. Mesdal on a class of partizan splitting games, answering questions first raised over 30 years ago. Mesdal is a joint effort of eleven co-authors from North America and New Zealand. Eight of the eleven attended the workshop and the number of co-authors had risen to twelve by the time the Workshop ended. In the end, between the talks and the discussions, there was simply too much to absorb in such a short time. The talks, surveys and several consequent papers are slated to appear as (tentatively titled) Games of No Chance 3 in the MSRI book series. 1 2 All the presentations were at a high standard and all had lively discussions during and after the time allotted. Some highlights were: Conway’s talk on lexicodes; Berlekamp’s overview Today’s View of Combinatorial Game Theory; and Fraenkel’s What hides beyond the curtain separating Nim from non-Nim games; Demaine’s talk on Dyson Telescopes and Moving Coin Puzzles also showed the complexity in some very new and some very old puzzles. However the highlights were the reports by: 1. Plambeck on a breakthrough in the analysis of impartial mis`ergames; 2. Siegel on extending the analysis of loopy games; 3. Friedman and Landsberg on applying renormalization techniques from physics to combinatorial games—this paper was both controversial and thought provoking and lead to the most discus- sions, including ones on the nature of truth and of proof; 4. Nakamura on the use of ‘cooling by 2’ to determine the winner in ‘races to capture’ in Go. One of the goals of the Workshop was to bring together researchers from mathematics and computer science. This was one of the talks that helped bridge the gap and engendered much discussion. The 30 minutes allotted to the talk was too short, and most participants stayed an extra hour (into the dinner-time) so as to hear the details. All of these were very new, very important results, produced only months before the Workshop. 1: Mis`ere Games: On page 146 of On Numbers and Games, in Chapter 12, “How to Lose When You Must,” John Conway writes: Note that in a sense, [mis´ere] restive games are ambivalent Nim-heaps, which choose their size (g0 or g) according to their company. There are many other games which exhibit behaviour of this type, and it would be very interesting to have some general theory for them. Questions about the analysis of mis´ereimpartial octal games were raised in [3, 6] and no good general analytical techniques have been developed apart from finding the genus sequence [3]. (See [1, 22], see also [8, 20]). In his presentation, Plambeck provided such a general theory, cast in the language of commutative semigroups. The mis`ereanalysis of a combinatorial game often proves to be far more difficult than its normal play version. In fact it is an open question (Plambeck) if there is a mis´ereimpartial game whose analysis is simpler than the normal play version and there is no know way of analyzing mis´ere partizan games ([15], Problem 9). To take a typical example, the normal play of Dawsons Chess was solved as early as 1956 by Guy and Smith [16], but even today, a complete mis`ere analysis has not been found. Guy tells the story [15]: “[Dawsons chess] is played on a 3 × n board with white pawns on the first rank and black pawns on the third. It was posed as a losing game (last-player-losing, now called mis`ere) so that capturing was obligatory. Fortunately, (because we still don‘t know how to play Mis`ere Dawsons Chess) I assumed, as a number of writers of that time and since have done, that the mis`ereanalysis required only a trivial adjustment of the normal (last-player-winning) analysis. This arises because Bouton, in his original analysis of Nim [5], had observed that only such a trivial adjustment was necessary to cover both normal and mis`ereplay...” But even for impartial games, in which the same options are available to both players, regardless of whose turn it is to move, Grundy & Smith [14] showed that the general situation in mis`ereplay soon gets very complicated, and Conway [6], (p. 140) confirmed that the situation can only be simplified to the microscopically small extent noticed by Grundy & Smith. In Chapter 13 of [3], the genus theory of impartial mis`ere disjunctive sums is extended signifi- cantly from its original presentation in chapter 7 (How to Lose When You Must) of Conways On Numbers and Games [6]. But excluding the tame games that play like Nim in mis`ere play, theres a remarkable paucity of example games that the genus theory completely resolves. For example, 3 the section Mis`ereKayles ([3], pg 411) promises, “Although several tame games arise in Kayles (see Chapter 4), wild games abounding and well need all our [genus-theoretic] resources to tackle it...” However, it turns out Kayles wasn‘t tackled at all. It was left to the amateur William L. Sibert to settle mis`ereKayles using completely different methods. One finds a description of his solution at end of the updated Chapter 13 in [4], and also in [22]. When normal play is in effect, every game with nimber G+(G) = k can be thought of as the nim heap k. No information about best play of the game is lost by assuming that G is in fact precisely the nim heap of size k. Moreover, in normal play, the nimber of a sum is just the nim-sum of the nimbers of the summands. In this sense every normal play impartial game position is simply a disguised version of Nim (see [3], Chapter 4, for a full discussion). Genera. When mis`ereplay is in effect, nimbers can still be defined but many inequivalent games are assigned the same nimber, and the outcome of a sum is not determined by nimber of the summands. These unfortunate facts lead directly to the apparent great complexity of many mis`ere analyses. Nevertheless progress can be made. The key definition, taken directly from [6], now at the bottom of page 141: In the analysis of many games, we need even more information than is provided by either of these values [G+ and G−], and so we shall define a more complicated symbol that we call the Go-value or genus. This is the symbol g.g0g1g2 ... + − − − where g = G (G), g0 = G (G), g1 = G (G + 2), g2 = G (G + 2 + 2), ..., where, in general, gn is the G−-value of the sum of G with n other games all equal to [the nim-heap of size] 2. At first sight, the genus symbol looks to be an potentially infinitely long symbol in its exponent. In practice, it can be shown that the gis always fall into an eventual period two pattern. By convention, the symbol is written down with a finite exponent with the understanding that its final two values repeat indefinitely. Evidently the exponent of a genus symbol of a game G is closely related to the outcome of sums of G with all multiples of mis`erenim heaps of size two. The genus computations are intended to illustrate the complexities of a mis`ereanalysis when the only tools available to be applied are those described in Chapter 13 of Winning Ways.
Load more

Recommended publications
  • Arxiv:2101.07237V2 [Cs.CC] 19 Jan 2021 Ohtedsg N Oprtv Nlsso Obntra Games
    TRANSVERSE WAVE: AN IMPARTIAL COLOR-PROPAGATION GAME INSPRIED BY SOCIAL INFLUENCE AND QUANTUM NIM Kyle Burke Department of Computer Science, Plymouth State University, Plymouth, New Hampshire, https://turing.plymouth.edu/~kgb1013/ Matthew Ferland Department of Computer Science, University of Southern California, Los Angeles, California, United States Shang-Hua Teng1 Department of Computer Science, University of Southern California, Los Angeles, California, United States https://viterbi-web.usc.edu/~shanghua/ Abstract In this paper, we study a colorful, impartial combinatorial game played on a two- dimensional grid, Transverse Wave. We are drawn to this game because of its apparent simplicity, contrasting intractability, and intrinsic connection to two other combinatorial games, one inspired by social influence and another inspired by quan- tum superpositions. More precisely, we show that Transverse Wave is at the intersection of social-influence-inspired Friend Circle and superposition-based Demi-Quantum Nim. Transverse Wave is also connected with Schaefer’s logic game Avoid True. In addition to analyzing the mathematical structures and com- putational complexity of Transverse Wave, we provide a web-based version of the game, playable at https://turing.plymouth.edu/~kgb1013/DB/combGames/transverseWave.html. Furthermore, we formulate a basic network-influence inspired game, called Demo- graphic Influence, which simultaneously generalizes Node-Kyles and Demi- arXiv:2101.07237v2 [cs.CC] 19 Jan 2021 Quantum Nim (which in turn contains as special cases Nim, Avoid True, and Transverse Wave.). These connections illuminate the lattice order, induced by special-case/generalization relationships over mathematical games, fundamental to both the design and comparative analyses of combinatorial games. 1Supported by the Simons Investigator Award for fundamental & curiosity-driven research and NSF grant CCF1815254.
    [Show full text]
  • Impartial Games
    Combinatorial Games MSRI Publications Volume 29, 1995 Impartial Games RICHARD K. GUY In memory of Jack Kenyon, 1935-08-26 to 1994-09-19 Abstract. We give examples and some general results about impartial games, those in which both players are allowed the same moves at any given time. 1. Introduction We continue our introduction to combinatorial games with a survey of im- partial games. Most of this material can also be found in WW [Berlekamp et al. 1982], particularly pp. 81{116, and in ONAG [Conway 1976], particu- larly pp. 112{130. An elementary introduction is given in [Guy 1989]; see also [Fraenkel 1996], pp. ??{?? in this volume. An impartial game is one in which the set of Left options is the same as the set of Right options. We've noticed in the preceding article the impartial games = 0=0; 0 0 = 1= and 0; 0; = 2: {|} ∗ { | } ∗ ∗ { ∗| ∗} ∗ that were born on days 0, 1, and 2, respectively, so it should come as no surprise that on day n the game n = 0; 1; 2;:::; (n 1) 0; 1; 2;:::; (n 1) ∗ {∗ ∗ ∗ ∗ − |∗ ∗ ∗ ∗ − } is born. In fact any game of the type a; b; c;::: a; b; c;::: {∗ ∗ ∗ |∗ ∗ ∗ } has value m,wherem =mex a;b;c;::: , the least nonnegative integer not in ∗ { } the set a;b;c;::: . To see this, notice that any option, a say, for which a>m, { } ∗ This is a slightly revised reprint of the article of the same name that appeared in Combi- natorial Games, Proceedings of Symposia in Applied Mathematics, Vol. 43, 1991. Permission for use courtesy of the American Mathematical Society.
    [Show full text]
  • Hexaflexagons, Probability Paradoxes, and the Tower of Hanoi
    HEXAFLEXAGONS, PROBABILITY PARADOXES, AND THE TOWER OF HANOI For 25 of his 90 years, Martin Gard- ner wrote “Mathematical Games and Recreations,” a monthly column for Scientific American magazine. These columns have inspired hundreds of thousands of readers to delve more deeply into the large world of math- ematics. He has also made signifi- cant contributions to magic, philos- ophy, debunking pseudoscience, and children’s literature. He has produced more than 60 books, including many best sellers, most of which are still in print. His Annotated Alice has sold more than a million copies. He continues to write a regular column for the Skeptical Inquirer magazine. (The photograph is of the author at the time of the first edition.) THE NEW MARTIN GARDNER MATHEMATICAL LIBRARY Editorial Board Donald J. Albers, Menlo College Gerald L. Alexanderson, Santa Clara University John H. Conway, F.R. S., Princeton University Richard K. Guy, University of Calgary Harold R. Jacobs Donald E. Knuth, Stanford University Peter L. Renz From 1957 through 1986 Martin Gardner wrote the “Mathematical Games” columns for Scientific American that are the basis for these books. Scientific American editor Dennis Flanagan noted that this column contributed substantially to the success of the magazine. The exchanges between Martin Gardner and his readers gave life to these columns and books. These exchanges have continued and the impact of the columns and books has grown. These new editions give Martin Gardner the chance to bring readers up to date on newer twists on old puzzles and games, on new explanations and proofs, and on links to recent developments and discoveries.
    [Show full text]
  • ES.268 Dynamic Programming with Impartial Games, Course Notes 3
    ES.268 , Lecture 3 , Feb 16, 2010 http://erikdemaine.org/papers/AlgGameTheory_GONC3 Playing Games with Algorithms: { most games are hard to play well: { Chess is EXPTIME-complete: { n × n board, arbitrary position { need exponential (cn) time to find a winning move (if there is one) { also: as hard as all games (problems) that need exponential time { Checkers is EXPTIME-complete: ) Chess & Checkers are the \same" computationally: solving one solves the other (PSPACE-complete if draw after poly. moves) { Shogi (Japanese chess) is EXPTIME-complete { Japanese Go is EXPTIME-complete { U. S. Go might be harder { Othello is PSPACE-complete: { conjecture requires exponential time, but not sure (implied by P 6= NP) { can solve some games fast: in \polynomial time" (mostly 1D) Kayles: [Dudeney 1908] (n bowling pins) { move = hit one or two adjacent pins { last player to move wins (normal play) Let's play! 1 First-player win: SYMMETRY STRATEGY { move to split into two equal halves (1 pin if odd, 2 if even) { whatever opponent does, do same in other half (Kn + Kn = 0 ::: just like Nim) Impartial game, so Sprague-Grundy Theory says Kayles ≡ Nim somehow { followers(Kn) = fKi + Kn−i−1;Ki + Kn−i−2 j i = 0; 1; :::;n − 2g ) nimber(Kn) = mexfnimber(Ki + Kn−i−1); nimber(Ki + Kn−i−2) j i = 0; 1; :::;n − 2g { nimber(x + y) = nimber(x) ⊕ nimber(y) ) nimber(Kn) = mexfnimber(Ki) ⊕ nimber(Kn−i−1); nimber(Ki) ⊕ nimber(Kn−i−2) j i = 0; 1; :::n − 2g RECURRENCE! | write what you want in terms of smaller things Howe do w compute it? nimber(K0) = 0 (BASE CASE) nimber(K1) = mexfnimber(K0) ⊕ nimber(K0)g 0 ⊕ 0 = 0 = 1 nimber(K2) = mexfnimber(K0) ⊕ nimber(K1); 0 ⊕ 1 = 1 nimber(K0) ⊕ nimber(K0)g 0 ⊕ 0 = 0 = 2 so e.g.
    [Show full text]
  • Combinatorial Game Theory
    Combinatorial Game Theory Aaron N. Siegel Graduate Studies MR1EXLIQEXMGW Volume 146 %QIVMGER1EXLIQEXMGEP7SGMIX] Combinatorial Game Theory https://doi.org/10.1090//gsm/146 Combinatorial Game Theory Aaron N. Siegel Graduate Studies in Mathematics Volume 146 American Mathematical Society Providence, Rhode Island EDITORIAL COMMITTEE David Cox (Chair) Daniel S. Freed Rafe Mazzeo Gigliola Staffilani 2010 Mathematics Subject Classification. Primary 91A46. For additional information and updates on this book, visit www.ams.org/bookpages/gsm-146 Library of Congress Cataloging-in-Publication Data Siegel, Aaron N., 1977– Combinatorial game theory / Aaron N. Siegel. pages cm. — (Graduate studies in mathematics ; volume 146) Includes bibliographical references and index. ISBN 978-0-8218-5190-6 (alk. paper) 1. Game theory. 2. Combinatorial analysis. I. Title. QA269.S5735 2013 519.3—dc23 2012043675 Copying and reprinting. Individual readers of this publication, and nonprofit libraries acting for them, are permitted to make fair use of the material, such as to copy a chapter for use in teaching or research. Permission is granted to quote brief passages from this publication in reviews, provided the customary acknowledgment of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication is permitted only under license from the American Mathematical Society. Requests for such permission should be addressed to the Acquisitions Department, American Mathematical Society, 201 Charles Street, Providence, Rhode Island 02904-2294 USA. Requests can also be made by e-mail to [email protected]. c 2013 by the American Mathematical Society. All rights reserved. The American Mathematical Society retains all rights except those granted to the United States Government.
    [Show full text]
  • On Structural Parameterizations of Node Kayles
    On Structural Parameterizations of Node Kayles Yasuaki Kobayashi Abstract Node Kayles is a well-known two-player impartial game on graphs: Given an undirected graph, each player alternately chooses a vertex not adjacent to previously chosen vertices, and a player who cannot choose a new vertex loses the game. The problem of deciding if the first player has a winning strategy in this game is known to be PSPACE-complete. There are a few studies on algorithmic aspects of this problem. In this paper, we consider the problem from the viewpoint of fixed-parameter tractability. We show that the problem is fixed-parameter tractable parameterized by the size of a minimum vertex cover or the modular-width of a given graph. Moreover, we give a polynomial kernelization with respect to neighborhood diversity. 1 Introduction Kayles is a two-player game with bowling pins and a ball. In this game, two players alternately roll a ball down towards a row of pins. Each player knocks down either a pin or two adjacent pins in their turn. The player who knocks down the last pin wins the game. This game has been studied in combinatorial game theory and the winning player can be characterized in the number of pins at the start of the game. Schaefer [10] introduced a variant of this game on graphs, which is known as Node Kayles. In this game, given an undirected graph, two players alternately choose a vertex, and the chosen vertex and its neighborhood are removed from the graph. The game proceeds as long as the graph has at least one vertex and ends when no vertex is left.
    [Show full text]
  • Mathfest 2018
    Abstracts of Papers Presented at MathFest 2018 Denver, CO August 1 – 4, 2018 Published and Distributed by The Mathematical Association of America Contents Invited Addresses 1 Earle Raymond Hedrick Lecture Series by Gigliola Staffilani . 1 Nonlinear Dispersive Equations and the Beautiful Mathematics That Comes with Them Lecture 1: Thursday, August 2, 11:00–11:50 AM, Plaza Ballroom A, B, & C, Plaza Building Lecture 2: Friday, August 3, 10:30–11:20 AM, Plaza Ballroom A, B, & C, Plaza Building Lecture 3: Saturday, August 4, 10:00–10:50 AM, Plaza Ballroom A, B, & C, Plaza Building . 1 AMS-MAA Joint Invited Address . 1 Gravity’s Action on Light: A Mathematical Journey by Arlie Petters Thursday, August 2, 10:00–10:50 AM, Plaza Ballroom A, B, & C, Plaza Building . 1 MAA Invited Address . 1 Inclusion-exclusion in Mathematics: Who Stays in, Who Falls out, Why It Happens, and What We Should Do About It by Eugenia Cheng Friday, August 3, 11:30–12:20 AM, Plaza Ballroom A, B, & C, Plaza Building . 1 Snow Business: Scientific Computing in the Movies and Beyond by Joseph Teran Saturday, August 4, 11:00–11:50 AM, Plaza Ballroom A, B, & C, Plaza Building . 1 Mathematical Medicine: Modeling Disease and Treatment by Lisette de Pillis Thursday, August 2, 9:00–9:50 AM, Plaza Ballroom A, B, & C, Plaza Building . 2 MAA James R.C. Leitzel Lecture . 2 The Relationship between Culture and the Learning of Mathematics by Talitha Washington Saturday, August 4, 9:00–9:50 AM, Plaza Ballroom A, B, & C, Plaza Building .
    [Show full text]
  • Math-GAMES IO1 EN.Pdf
    Math-GAMES Compendium GAMES AND MATHEMATICS IN EDUCATION FOR ADULTS COMPENDIUMS, GUIDELINES AND COURSES FOR NUMERACY LEARNING METHODS BASED ON GAMES ENGLISH ERASMUS+ PROJECT NO.: 2015-1-DE02-KA204-002260 2015 - 2018 www.math-games.eu ISBN 978-3-89697-800-4 1 The complete output of the project Math GAMES consists of the here present Compendium and a Guidebook, a Teacher Training Course and Seminar and an Evaluation Report, mostly translated into nine European languages. You can download all from the website www.math-games.eu ©2018 Erasmus+ Math-GAMES Project No. 2015-1-DE02-KA204-002260 Disclaimer: "The European Commission support for the production of this publication does not constitute an endorsement of the contents which reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein." This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. ISBN 978-3-89697-800-4 2 PRELIMINARY REMARKS CONTRIBUTION FOR THE PREPARATION OF THIS COMPENDIUM The Guidebook is the outcome of the collaborative work of all the Partners for the development of the European Erasmus+ Math-GAMES Project, namely the following: 1. Volkshochschule Schrobenhausen e. V., Co-ordinating Organization, Germany (Roland Schneidt, Christl Schneidt, Heinrich Hausknecht, Benno Bickel, Renate Ament, Inge Spielberger, Jill Franz, Siegfried Franz), reponsible for the elaboration of the games 1.1 to 1.8 and 10.1. to 10.3 2. KRUG Art Movement, Kardzhali, Bulgaria (Radost Nikolaeva-Cohen, Galina Dimova, Deyana Kostova, Ivana Gacheva, Emil Robert), reponsible for the elaboration of the games 2.1 to 2.3 3.
    [Show full text]
  • Combinatorial Game Complexity: an Introduction with Poset Games
    Combinatorial Game Complexity: An Introduction with Poset Games Stephen A. Fenner∗ John Rogersy Abstract Poset games have been the object of mathematical study for over a century, but little has been written on the computational complexity of determining important properties of these games. In this introduction we develop the fundamentals of combinatorial game theory and focus for the most part on poset games, of which Nim is perhaps the best- known example. We present the complexity results known to date, some discovered very recently. 1 Introduction Combinatorial games have long been studied (see [5, 1], for example) but the record of results on the complexity of questions arising from these games is rather spotty. Our goal in this introduction is to present several results— some old, some new—addressing the complexity of the fundamental problem given an instance of a combinatorial game: Determine which player has a winning strategy. A secondary, related problem is Find a winning strategy for one or the other player, or just find a winning first move, if there is one. arXiv:1505.07416v2 [cs.CC] 24 Jun 2015 The former is a decision problem and the latter a search problem. In some cases, the search problem clearly reduces to the decision problem, i.e., having a solution for the decision problem provides a solution to the search problem. In other cases this is not at all clear, and it may depend on the class of games you are allowed to query. ∗University of South Carolina, Computer Science and Engineering Department. Tech- nical report number CSE-TR-2015-001.
    [Show full text]
  • AK Softwaretechnology
    Algorithmen und Spiele Games, NIM-Theory Oswin Aichholzer, University of Technology, Graz (Austria) Algorithmen und Spiele, Aichholzer NIM & Co 0 What is a (mathematical) game? . 2 players [ A(lice),B(ob) / L(eft),R(ight) / …] . the players move in turns (A,B,A,B,A,B …) . Both players have complete information (no hidden cards …) . No randomness (flipping coins, rolling dice ...) . A (finite) set of positions, one (or more) marked as starting position Algorithmen und Spiele, Aichholzer NIM & Co 1 What is a game, cont.? . For each position there exists a set of successors, (possibly empty) . A players legal move: transformation from one position to a successor . Normal play: the first player which can NOT move loses (the other player wins) . Every game ends after a finite number of moves . No draws Algorithmen und Spiele, Aichholzer NIM & Co 2 Chocolate game (Chomp) B A A A A B B B Algorithmen und Spiele, Aichholzer NIM & Co 3 Who wins a game? . Which player wins the game (A,B)? . First player (starting) or second player? . Assume both players play optimal: There are ‘First-Player-win’ und ‘Second- Player-win’ games. What is the optimal strategy? Play Chomp! Algorithmen und Spiele, Aichholzer NIM & Co 4 Chocolate game (again) • Tweedledum-Tweedledee- principle A Alice in Wonderland by Lewis Carrol Algorithmen und Spiele, Aichholzer NIM & Co 5 NIM . Who knowns NIM? . n piles of k1,…,kn > 0 coins . valid moves: . chose a single (non-empty) pile . remove an arbitrary number of coins from the pile (at least one, at most all) . Remember: normal play: the last one to make a valid move wins Algorithmen und Spiele, Aichholzer NIM & Co 6 Prime-game .
    [Show full text]
  • Daisies, Kayles, Sibert-Conway and the Decomposition in Miske Octal
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Theoretical Computer Science 96 (1992) 361-388 361 Elsevier Mathematical Games Daisies, Kayles, and the Sibert-Conway decomposition in miske octal games Thane E. Plambeck Compuler Science Department, Stanford University, StanJord, Cal@nia 94305, USA Communicated by R.K. Guy Received November 1990 Revised June 1991 Abstract Plambeck, T.E., Daisies, Kayles, and the Sibert-Conway decomposition in misere octal games, Theoretical Computer Science 96 (1992) 361-388. Sibert and Conway [to appear] have solved a long-standing open problem in combinatorial game theory by giving an efficient algorithm for the winning misere play of Kay/es, an impartial two-player game of complete information first described over 75 years ago by Dudeney (1910) and Loyd (1914). Here, we extend the SiberttConway method to construct a similar winning strategy for the game of Daisies (octal code 4.7) and then more generally solve all misere play finite octal games with at most 3 code digits and period two nim sequence * 1, * 2, * 1, * 2, 1. Introduction She Loves Me, She Loves Me Not is a two-player game that can be played with one or more daisies, such as portrayed in Fig. 1. To play the game, the two players take turns pulling one petal off a daisy. In normal play, the player taking the last petal is defined to be the winner. Theorem 1.1 is not difficult to prove. Theorem 1.1. In normal play of the game She Loves Me, She Loves Me Not, a position is a win for the jrst player if and only zifit contains an odd number of petals.
    [Show full text]
  • Numbers 1 to 100
    Numbers 1 to 100 PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Tue, 30 Nov 2010 02:36:24 UTC Contents Articles −1 (number) 1 0 (number) 3 1 (number) 12 2 (number) 17 3 (number) 23 4 (number) 32 5 (number) 42 6 (number) 50 7 (number) 58 8 (number) 73 9 (number) 77 10 (number) 82 11 (number) 88 12 (number) 94 13 (number) 102 14 (number) 107 15 (number) 111 16 (number) 114 17 (number) 118 18 (number) 124 19 (number) 127 20 (number) 132 21 (number) 136 22 (number) 140 23 (number) 144 24 (number) 148 25 (number) 152 26 (number) 155 27 (number) 158 28 (number) 162 29 (number) 165 30 (number) 168 31 (number) 172 32 (number) 175 33 (number) 179 34 (number) 182 35 (number) 185 36 (number) 188 37 (number) 191 38 (number) 193 39 (number) 196 40 (number) 199 41 (number) 204 42 (number) 207 43 (number) 214 44 (number) 217 45 (number) 220 46 (number) 222 47 (number) 225 48 (number) 229 49 (number) 232 50 (number) 235 51 (number) 238 52 (number) 241 53 (number) 243 54 (number) 246 55 (number) 248 56 (number) 251 57 (number) 255 58 (number) 258 59 (number) 260 60 (number) 263 61 (number) 267 62 (number) 270 63 (number) 272 64 (number) 274 66 (number) 277 67 (number) 280 68 (number) 282 69 (number) 284 70 (number) 286 71 (number) 289 72 (number) 292 73 (number) 296 74 (number) 298 75 (number) 301 77 (number) 302 78 (number) 305 79 (number) 307 80 (number) 309 81 (number) 311 82 (number) 313 83 (number) 315 84 (number) 318 85 (number) 320 86 (number) 323 87 (number) 326 88 (number)
    [Show full text]