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Finding Short Right-Hand-on-the-Wall Walks in Graphs

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Structural Information and Communication Complexity (SIROCCO 2005)

Part of the book series: Lecture Notes in Computer Science ((LNTCS,volume 3499))

Abstract

We consider the problem of perpetual traversal by a single agent in an anonymous undirected graph G. Our requirements are: (1) deterministic algorithm, (2) each node is visited within O(n) moves, (3) the agent uses no memory, it can use only the label of the link via which it arrived to the current node, (4) no marking of the underlying graph is allowed and (5) no additional information is stored in the graph (e.g. routing tables, spanning tree) except the ability to distinguish between the incident edges (called Local Orientation).

This problem is unsolvable, as has been proven in [9,28] even for much less restrictive setting. Our approach is to somewhat relax the requirement (5). We fix the following traversal algorithm: “Start by taking the edge with the smallest labelx. Afterwards, whenever you come to a node, continue by taking the successor edge (in the local orientation) to the edge via which you arrived” and ask whether it is for every undirected graph possible to assign the local orientations in such a way that the resulting perpetual traversal visits every node in O(n) moves.

We give a positive answer to this question, by showing how to construct such local orientations. This leads to an extremely simple, memoryless, yet efficient traversal algorithm.

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References

  1. Albers, S., Henzinger, M.R.: Exploring unknown environments. SIAM Journal on Computing 29, 1164–1188 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  2. Alon, N., Azar, Y., Ravid, Y.: Universal sequences for complete graphs. Discrete Appl. Math. 27(1-2), 25–28 (1990)

    Article  MATH  MathSciNet  Google Scholar 

  3. Awerbuch, B., Betke, M., Singh, M.: Piecemeal graph learning by a mobile robot. Information and Computation 152, 155–172 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  4. Bar-Noy, A., Borodin, A., Karchmer, M., Linial, N., Werman, M.: Bounds on universal sequences. SIAM J. Comput. 18, 268–277 (1989)

    Article  MATH  MathSciNet  Google Scholar 

  5. Bender, M., Fernandez, A., Ron, D., Sahai, A., Vadhan, S.: The power of a pebble: Exploring and mapping directed graphs. In: Proc. of STOC 1998, pp. 269–287 (1998)

    Google Scholar 

  6. Bender, M., Slonim, D.K.: The power of team exploration: two robots can learn unlabeled directed graphs. In: Proc. of FOCS 1994, pp. 75–85 (1994)

    Google Scholar 

  7. Blum, A., Raghavan, P., Schieber, B.: Navigating in unfamiliar geometric terrain. SIAM Journal on Computing 26, 110–137 (1997)

    Article  MATH  MathSciNet  Google Scholar 

  8. Blum, M., Kozen, D.: On the power of the compass (or, why mazes are easier to search than graphs). In: Proc. of FOCS 1978, pp. 132–142 (1978)

    Google Scholar 

  9. Budach, L.: Automata and labyrinths. Math. Nachrichten, 195–282 (1978)

    Google Scholar 

  10. Buhrman, H., Franklin, M., Garay, J.A., Hoepman, J.-H., Tromp, J., Vitányi, P.: Mutual search. J. ACM 46(4), 517–536 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  11. Deng, X., Kameda, T., Papadimitriou, C.H.: How to learn an unknown environment i: The rectilinear case. Journal of the ACM 45, 215–245 (1998)

    Article  MATH  MathSciNet  Google Scholar 

  12. Deng, X., Papadimitriou, C.H.: Exploring an unknown graph. Journal of Graph Theory 32(3), 265–297 (1999)

    Article  MATH  MathSciNet  Google Scholar 

  13. Dessmark, A., Pelc, A.: Optimal graph exploration without good maps. In: Möhring, R.H., Raman, R. (eds.) ESA 2002. LNCS, vol. 2461, pp. 374–386. Springer, Heidelberg (2002)

    Chapter  Google Scholar 

  14. Diks, K., Fraigniaud, P., Kranakis, E., Pelc, A.: Tree exploration with little memory. Journal of Algorithms 51, 38–63 (2004)

    Article  MATH  MathSciNet  Google Scholar 

  15. Dobrev, S., Flocchini, P., Prencipe, G., Santoro, N.: Finding a black hole in an arbitrary network: optimal mobile agents protocols. In: Proc. of PODC 2002, pp. 153–162 (2002)

    Google Scholar 

  16. Duncan, C.A., Kobourov, S.G., Kumar, V.S.A.: Optimal constrained graph exploration. In: 12th ACM-SIAM Symposium on Discrete Algorithms (SODA 2001), pp. 807–814 (2001)

    Google Scholar 

  17. Flocchini, P., Mans, B., Santoro, N.: On the impact of sense of direction on communication complexity. Information Processing Letters 63(1), 23–31 (1997)

    Article  MathSciNet  Google Scholar 

  18. Flocchini, P., Mans, B., Santoro, N.: Sense of direction: definition, properties and classes. Networks 32(3), 165–180 (1998)

    Article  MATH  MathSciNet  Google Scholar 

  19. Fraigniaud, P., Gavoille, C., Mans, B.: Interval routing schemes allow broadcasting with linear message-complexity. Journal of Distributed Computing 14(4), 217–229 (2001)

    Article  Google Scholar 

  20. Fraigniaud, P., Ilcinkas, D.: Digraph exploration with little memory. In: Diekert, V., Habib, M. (eds.) STACS 2004. LNCS, vol. 2996, pp. 246–257. Springer, Heidelberg (2004)

    Chapter  Google Scholar 

  21. Fraigniaud, P., Ilcinkas, D., Peer, G., Pelc, A., Peleg, D.: Graph exploration by a finite automaton. In: Fiala, J., Koubek, V., Kratochvíl, J. (eds.) MFCS 2004. LNCS, vol. 3153, pp. 451–462. Springer, Heidelberg (2004)

    Chapter  Google Scholar 

  22. Friege, U.: A tight upper bound on the cover time for random walks on graphs. Random Structures and Algorithms 6(1), 51–54 (1995)

    Article  MathSciNet  Google Scholar 

  23. Hoory, S., Wigderson, A.: Universal traversal sequences for expander graphs. Inf. Process. Lett. 46(2), 67–69 (1993)

    Article  MATH  MathSciNet  Google Scholar 

  24. Kozen, D.: Automata and planar graphs. In: Proc. of Fundations Computatial Theory (FCT 1979), pp. 243–254 (1979)

    Google Scholar 

  25. Panaite, P., Pelc, A.: Impact of topographic information on graph exploration efficiency. Networks 36

    Google Scholar 

  26. Rabin, M.O.: Maze threading automata. Technical Report Seminar Talk, University of California at Berkeley (October 1967)

    Google Scholar 

  27. Reingold, O.: Undirected st-connectivity in log-space. Electronic Colloquium on Computational Complexity 94 (2004)

    Google Scholar 

  28. Rollik, H.A.: Automaten in planaren graphen. Acta Informatica 13, 287–298 (1980)

    Article  MATH  MathSciNet  Google Scholar 

  29. Roo, N., Hareti, S., Shi, W., Iyengar, S.: Robot navigation in unknown terrains: Introductory survey of length, non-heuristic algorithms. Technical Report ORNL/TM12410, Oak Ridge National Lab (1993)

    Google Scholar 

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Dobrev, S., Jansson, J., Sadakane, K., Sung, WK. (2005). Finding Short Right-Hand-on-the-Wall Walks in Graphs. In: Pelc, A., Raynal, M. (eds) Structural Information and Communication Complexity. SIROCCO 2005. Lecture Notes in Computer Science, vol 3499. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11429647_12

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  • DOI: https://doi.org/10.1007/11429647_12

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-26052-3

  • Online ISBN: 978-3-540-32073-9

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