Abstract
To study different implementations of arrays, we present four results on the time complexities of on-line simulations between multidimensional Turing machines and random access machines (RAMs). First, everyd-dimensional Turing machine of time complexityt can be simulated by a log-cost RAM running inO(t(logt)1−(1/d)(log logt)1/d) time. Second, everyd-dimensional Turing machine of time complexityt can be simulated by a unit-cost RAM running inO(t/(logt)1/d) time, provided that the input length iso(t/(logt)1/d). Third, there is a log-cost RAMR of time complexityO(n), wheren is the input length, such that, for anyd-dimensional Turing machineM that simulatesR on-line,M requires Ω(n 1 + (1/d))/(logn(log logn)1 + (1/d))) time. Fourth, every unit-cost RAM of time complexityt can be simulated by ad-dimensional Turing machine inO(t 2(logt)1/2) time ifd = 2, and inO(t 2) time ifd ≥ 3. This result uses the weight-balanced trees of Nievergelt and Reingold.
Similar content being viewed by others
References
A. Aggarwal, B. Alpern, A. K. Chandra, and M. Snir (1987), A model for hierarchical memory,Proc. 19th Ann. ACM Symp. on Theory of Computing, pp. 305–314.
B. Alpern, L. Carter, and E. Feig (1990), Uniform memory hierarchies,Proc. 31st Ann. Symp. on Foundations of Computer Science, pp. 600–608.
S. A. Cook and R. A. Reckhow (1973), Time bounded random access machines,J. Comput. System Sci., vol. 7, pp. 354–375.
Z. Galil (1976), Two fast simulations which imply some fast string matching and palindrome-recognition algorithms,Inform. Process. Lett., vol. 4, no. 4, pp. 85–87.
D. Y. Grigor'ev (1979), Time complexity of multidimensional Turing machines,Zap. naucn. sem., vol. 88, pp. 47–55.
F. C. Hennie (1966), On-line Turing machine computations,IEEE Trans. Electron. Comput., vol. 15, no. 1, pp. 35–44.
J. Hopcroft, W. Paul, and L. Valiant (1975), On time versus space and related problems,Proc. 16th Ann. Symp. on Foundations of Computer Science, pp. 57–64.
J. Katajainen, J. van Leeuwen, and M. Penttonen (1988), Fast simulation of Turing machines by random access machines,SIAM J. Comput., vol. 17, no. 1, pp. 77–88.
D. E. Knuth (1973),The Art of Computer Programming, Vol. 1, 2nd edn., Addison-Wesley, Reading, MA.
M. Li and P. M. B. Vitányi (1990), Kolmogorov complexity and its applications, inHandbook of Theoretical Computer Science (J. van Leeuwen, Managing Editor), Elsevier, Amsterdam, and M.I.T. Press, Cambridge, MA., pp. 187–254.
M. C. Loui (1982), Simulations among multidimensional Turing machines,Theoret. Comput. Sci., vol. 21, no. 2, pp. 145–161.
M. C. Loui (1983), Optimal dynamic embedding of trees into arrays,SIAM J. Comput., vol. 12, no. 3, pp. 463–472.
M. C. Loui and D. R. Luginbuhl (1990), Optimal on-line simulation of tree machines by random access machines.,SIAM J. Comput., to appear.
D. R. Luginbuhl (1990), Computational complexity of random access models, Ph.D. Dissertation, Univ. Illinois at Urbana-Champaign, Jan. 1990. Also Tech. Rept. ACT-110, Coordinated Science Lab., UILU-ENG-90-2201, Jan. 1990.
G. K. Manacher (1982), Steady-paced output and fractional on-line algorithms on a RAM,Inform. Process. Lett., vol. 15, no. 2, pp. 47–52.
J. Nievergelt and E. M. Reingold (1973), Binary search trees of bounded balance,SIAM J. Comput., vol. 2, no. 1, pp. 33–43.
N. Pippenger (1982), Probabilistic simulations,Proc. 14th Ann. ACM Symp. on Theory of Computing, pp. 17–26.
N. Pippenger and M. J. Fischer (1979), Relations among complexity measures,J. Assoc. Comput. Mach., vol. 19, pp. 361–381.
E. M. Reingold, J. Nievergelt, and N. Deo (1977),Combinatorial Algorithms, Prentice-Hall, Englewood Cliffs, NJ.
J. M. Robson (1990), Random access machines with multi-dimensional memories,Inform. Process. Lett., vol. 34, no. 5, pp. 265–266.
A. Schönhage (1980), Storage modification machines,SIAM J. Comput., vol. 9, no. 3, pp. 490–508.
A. Schönhage (1988), A nonlinear lower bound for random-access machines under logarithmic cost,J. Assoc. Comput. Mach., vol. 35, no. 3, pp. 748–754.
C. Slot and P. van Emde Boas (1988), The problem of space invariance for sequential machines,Inform. Comput., vol. 77, pp. 93–122.
P. van Emde Boas (1990), Machine models and simulations, inHandbook of Theoretical Computer Science (J. van Leeuwen, Managing Editor), Elsevier, Amsterdam, and M.I.T. Press, Cambridge, MA, pp. 1–66.
K. Wagner and G. Weehsung (1986),Computational Complexity, Reidel, Dordrecht.
Author information
Authors and Affiliations
Additional information
This paper was prepared while M. C. Loui was visiting the National Science Foundation in Washington, DC, and the Institute for Advanced Computer Studies, University of Maryland, College Park, MD. The views, opinions, and conclusions in this paper are those of the authors and should not be construed as an official position of the National Science Foundation, Department of Defense, U.S. Air Force, or any other U.S. government agency. The research of M. C. Loui was supported by the National Science Foundation under Grant CCR-8922008.
Rights and permissions
About this article
Cite this article
Loui, M.C., Luginbuhl, D.R. The complexity of on-line simulations between multidimensional turing machines and random access machines. Math. Systems Theory 25, 293–308 (1992). https://doi.org/10.1007/BF01213861
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01213861