publications     (and supervised theses)

  • interview in German newspaper Neues Deutschland, September 3/4 2016, Vorerst bleibt Hex verhext
                (c) courtesy Neues Deutschland 2016
  • R Hayward, N Weninger, K Young, K Takada, T Zhang
                MoHex Wins 2016 Hex Tournaments in Leiden
                to appear in ICGA Journal
  • K Young, R Hayward
                A Reverse Hex Solver
                to appear in Proc. of Computers and Games 2016
  • K Young, G Vasan, R Hayward
                NeuroHex: A Deep Q-Learning Hex Agent
                to appear in Proc. Computer Games Workshop, IJCAI 2016
  • R Hayward, J Pawlewicz, K Takada, T Van der Valk
                MoHex Wins 2015 Hex Tournaments in Leiden
                to appear in ICGA Journal
  • R. Hayward
                Good Pass Moves in No-Draw HyperHex: Two Proverbs
                to appear in Games of No Chance V, Cambridge University Press.
  • J. Pawlewicz, R. Hayward
                Feature Strength and Parallelization of Sibling Conspiracy Number Search
                Advances in Computers Games 2015, Plaat et al. (eds), Springer LNCS (to appear).
  • J. Pawlewicz, R. Hayward
                Sibling Conspiracy Number Search
                Proc. 8th International Symposium Combinatorial Search (SoCS 2015), AAAI Press, July (2015) 105-112.
  • J. Pawlewicz, R. Hayward
                Stronger Virtual Connections in Hex
                IEEE Transactions on Computational Intelligence and AI in Games 7 (2) June (2015) 156-166
  • B Hauer, R Hayward, G Kondrak
                Solving Substitution Ciphers with Combined Language Models
                Proc. COLING 2014 (25th Intl Conf on Computational Linguistics) (2014) 2314-2325
  • S Huneke, R Hayward, B Toft
                A winning strategy for 3xn cylindrical hex
                Discrete Math 331 (2014) 93-97
  • R Hayward, B Arneson, S-C Huang, J Pawlewicz
                MoHex Wins Hex Tournament   pic
                ICGA Journal 36-3 (Sept 2013) 180-183
  • J. Pawlewicz, R. Hayward
                Scalable Parallel Depth First Proof Number Search
                Proc. Computers and Games CG2013, Springer LNCS 8427 (2014) 138-150
  • S. Huang, B. Arneson, R. Hayward, M. Mueller, J. Pawlewicz
                MoHex 2.0: a pattern-based MCTS Hex player
                Proc. Computers and Games CG2013, Springer LNCS 8427 (2014) 60-71
  • P. Henderson, R. Hayward
                Captured-Reversible Moves and Star-Domination in Hex
                Integers 13 (2013) #G1
  • Henry Brause, R. Hayward, Martin Mueller, Abdul Qadir, David Spies,
                Blunder Cost in Go and Hex
                Advances in Computer Games, H.J.van den Herik and A. Plaat (eds), Springer-Verlag Berlin, LNCS 7168 (2012) 220-229
  • R. Hayward
                MoHex Wins Hex Tournament
                ICGA Journal 35-2 (June 2012) 124-127
  • R. Hayward, B. Toft, P. Henderson
                How to Play Reverse Hex
                Discrete Mathematics 312-1 (6 Jan 2012) 148-156
  • B. Arneson, R. Hayward, P. Henderson
                Monte Carlo Tree Search in Hex
                IEEE Transactions on Computational Intelligence and AI in Games 2-4 Dec 2010 251-257
  • B. Arneson, R. Hayward, P. Henderson
                Solving Hex: Beyond Humans
                Computers and Games, 7th Int'l Conf: CG 2010 (Kanazawa)
                H.J. van den Herik and H. Iida and A. Plaat (eds.), Springer LNCS 6515, 2011, pp 1-10
  • P. Henderson and R. Hayward
                A Hex Handicap Strategy
                to appear in Games of No Chance 4, Cambridge University Press
  • B. Arneson, R. Hayward, P. Henderson,
                MoHex Wins Hex Tournament (16th Computer Olympiad 2010 Kanazawa)
                ICGA Journal 33-3 (Sept 2010) 181-187
  • P. Henderson, B. Arneson, and R. Hayward
                Hex, Braids, the Crossing Rule, and XH-search
                Advances in Computer Games, 12th Int'l Conf: ACG 2009 (Pamplona)
                H.J. van den Herik and P. Spronck eds., Springer LNCS 6048 88-98 (2010)
  • B. Arneson, R. Hayward, P. Henderson,
                MoHex Wins Hex Tournament (14th Computer Olympiad 2009 Pamplona)
                ICGA Journal 32-2 (June 2009) 114-116
  • B. Arneson, R. Hayward, P. Henderson,
                Wolve 2008 Wins Hex Tournament (13th Computer Olympiad 2008 Beijing)
                ICGA Journal 32-1 (March 2009) 49-53
  • P. Henderson, B. Arneson, and R. Hayward
                Solving 8x8 Hex
                Proc. IJCAI-09 505-510 (2009)
  • R. Hayward
                A puzzling Hex primer
                in Games of No Chance 3, M.H. Albert and R.J. Nowakowski eds.,
                Cambridge University Press (MSRI publications) 56:151--162 (2009)
  • P. Henderson and R. Hayward
                Probing the 4-3-2 Edge Template in Hex
                H.J. van den Herik et al. eds.: CG 2008, Springer LNCS 5131 (2008) 229--240
  • R. Hayward, B. Arneson, and P. Henderson
                Automatic Strategy Verification for Hex
                Springer LNCS 4630 (2007) 112--121
  • R. Hayward
                The Story of Perfectly Orderable Graphs
                Graphs and Combinatorics 23:269--273 (2007)
  • R. Hayward, J. Spinrad, and R. Sritharan
                Improved algorithms for weakly chordal graphs
                Transactions on Algorithms 3:2 (2007) 14pp
  • Y. Bjornsson, R. Hayward, M. Johanson, J. van Rijswijck,
                Dead Cell Analysis in Hex and the Shannon Game,
                in Graph Theory in Paris: Proc. of a Conference in Memory
                of Claude Berge (GT04 Paris), Birkauser 2007, pp 45-60
  • R. Hayward and J. van Rijswijck,
                Hex and Combinatorics
                Discrete Math 306 (2006) 2515-2528
  • R. Greiner, R. Hayward, M. Jankowska, M. Molloy,
                Finding optimal satisficing strategies for and-or trees,
                Artificial Intelligence 170 (2006) 19-58
  • R. Hayward,
                Six wins Hex Tournament (11th Computer Olympiad 2006 Torino)
                ICGA Journal 29-3 (Sept 2006) 163-165
  • R. Hayward, Y. Bjornsson, M. Johanson, N. Po, J. van Rijswijck,
                Solving 7x7 Hex with domination, fill-in, and virtual connections (part I)
                (part II),
                Theoretical Computer Science 349 (2005) 123-139
                download the proof trees here
  • R. Hayward,
                A Note on Domination in Hex, manuscript (2003;revised 2004).
  • G. Melis and R. Hayward,
                Six wins Hex Tournament (8th Computer Olympiad 2003 Graz),
                ICGA Journal 26-4 (Dec. 2003) 277-280.
  • R. Hayward,
                Berge and the Art of Hex (draft),
                book chapter submitted to Princeton University Press (2003)
  • R. Hayward, R. Shamir,
                A note on tolerance graph recognition,
                Discrete Applied Math 143:307-311 (2004)
  • R. Hayward, P. Kearney, A. Malton,
                NeST graphs,
                Discrete Applied Mathematics 121 (June 2002), 139-153
  • R. Hayward, S. Hougardy, B.A. Reed,
                Polynomial time recognition of P4-structure,
                Proc. 13th SODA (2002) 382-389
  • R. Hayward & W. Lenhart, Bichromatic P4 composition schemes for perfect orderability,
                Discrete Applied Math 141 (2004) 161-183
  • R. Hayward and B.A. Reed, Forbidding Holes and Antiholes in Perfect Graphs (eds. J. Ramirez Alfonsin and B. Reed), Wiley and Sons, (2001) 113-137
  • R. Hayward, J. Spinrad, R. Sritharan, Weakly Chordal Graph Algorithms via Handles, Proc. 11th SODA (2000) 42-49
  • R. Hayward, Bull-free Weakly Chordal Perfectly Orderable Graphs, Graphs and Combinatorics 17 (2000) 479-500
  • E. Eschen, R. Hayward, J. Spinrad, R. Sritharan, Weakly triangulated comparability graphs, SIAM J. Comput. 29 (1999) 378-386
  • R. Hayward, Meyniel Weakly Triangulated Graphs II: A Theorem of Dirac Discrete Applied Mathematics 78 (1997) 283-289
  • R. Hayward, Meyniel Weakly Triangulated Graphs I: Co-perfect orderability Discrete Applied Mathematics 73 (1997) 199-210
  • P. Kearney, R. Hayward, H. Meijer, Phylogeny from relative dissimilarity, Algorithmica 25 (1999) 196-221, expanded version of
        P. Kearney, R. Hayward, H. Meijer, Inferring evolutionary trees from ordinal data, Proc. 8th SODA (1997) 418-426
  • R. Hayward, Recognizing P3-structure: A Switching Approach, Journal Comb. Theory (Series B) 66 No. 2 (1996) 247-262
  • R. Hayward, Generating Weakly Triangulated Graphs, Journal of Graph Theory 21 (1996) 67-69    demonstration applet.
  • R. Hayward, Discs in Unbreakable Graphs, Graphs and Combinatorics 11 (1995) 249-254
  • C. McDiarmid & R. Hayward, Large Deviations for Quicksort, Journal of Algorithms 21 (1996) 476-507, expanded version of
        C. McDiarmid & R. Hayward, Strong Concentration for Quicksort, Proc. 3rd SODA (1992) 414-421
  • R. Hayward & C. McDiarmid, Average case analysis of heap building by repeated insertion, Journal of Algorithms 12 (1991) 126-153
  • R. Hayward, A note on the circle containment problem, Discrete Comput. Geom. 4:263-264 (1989)
  • R. Hayward, C. Hoang, F. Maffray, Optimizing Weakly Triangulated Graphs, Graphs and Combinatorics 5:339-349 (1989), 6:33-35 (1990)
  • R. Hayward, D. Rappaport, R. Wenger, Some extremal results on circles containing points, Discrete Comput. Geom 4:253-258 (1989)
  • R. Hayward, A Lower Bound for the Optimal Crossing-Free Hamiltonian Cycle Problem, Discrete Comput. Geom 2:327-343 (1987)
  • R. Hayward, Weakly triangulated graphs, Journal Comb. Theory (Series B) 39 (1985) 200-208
  • R. Hayward, Two Classes of Perfect Graphs, Phd thesis, McGill University, 1986.
  • R. Hayward, The optimal crossing-free hamilton cycle problem for planar drawings of the complete graph, MSc thesis, Queen's University (Kingston), 1982.

    supervised theses

  • E. Johnson, On Finding Hajos Constructions, MSc thesis, University of Alberta, 2015
  • T. Ewalds, Playing and Solving Havannah, MSc thesis, University of Alberta, 2012
  • P. Henderson, Playing and Solving Hex, Phd thesis, University of Alberta, 2010
  • S. Ghosh, Heuristics for Integer Programs, Phd thesis, University of Alberta, 2007
  • J. van Rijswijck, Set Colouring Games, Phd thesis, University of Alberta, 2006
  • J. Nastos, (P5, P5-complement)-free Graphs, MSc thesis, University of Alberta, 2006
  • W.S. Kennedy, Strictly Chordal Graphs and Phylogenetic Roots, MSc thesis, University of Alberta, 2005
  • M. Jankowska, Probabilistic And-Or Tree Resolution, MSc thesis, University of Alberta, 2004
  • P. Kearney, On NeST Graphs, MSc thesis, Queen's University, 2003
  • R. Krueger, A Polynomial Time Algorithm for Line Segment Diagram Isomorphism, MSc thesis, University of Alberta, 2002