Abstract
Recently, Charikar et. al. investigated the problem of evaluating AND/OR trees, with non uniform costs on its leaves, under the perspective of the competitive analysis. For an AND-OR tree T they presented a μ(T)-competitive deterministic polynomial time algorithm, where μ(T) is the number of leaves that must be read, in the worst case, in order to determine the value of T. Furthermore, they prove that μ(T) is a lower bound on the deterministic competitiveness, which assures the optimality of their algorithm.
The power of randomization in this context has remained as an open question. Here, we give a step towards solving this problem by presenting a 0.792 μ(T)-competitive randomized polynomial time algorithm. This contrasts with the best known lower bound μ(T)/2.
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References
Tarsi, M.: Optimal search on some game trees. Journal of the ACM 30, 389–396 (1983)
Snir, M.: Lower bounds on probabilistic linear decision trees. Theoretical Computer Science 38, 69–82 (1985)
Saks, M., Wigderson, A.: Probabilistic Boolean decision trees and the complexity of evaluating game trees. In: 27th Annual Symposium on Foundations of Computer Science, Toronto, Ontario, Canada, pp. 29–38. IEEE, Los Alamitos (1986)
Charikar, F., Guruswami, K., Raghavan, S.: Query strategies for priced information. JCSS: Journal of Computer and System Sciences 64 (2002)
Hellerstein, J.M.: Optimization techniques for queries with expensive methods. ACM Transactions on Database Systems 23, 113–157 (1998)
Laber, E., Carmo, R., Kohayakawa, Y.: Query priced information on database: The conjunctive case. In: Farach-Colton, M. (ed.) LATIN 2004. LNCS, vol. 2976, pp. 6–15. Springer, Heidelberg (2004)
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Laber, E.S. (2004). A Randomized Competitive Algorithm for Evaluating Priced AND/OR Trees. In: Diekert, V., Habib, M. (eds) STACS 2004. STACS 2004. Lecture Notes in Computer Science, vol 2996. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-24749-4_44
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DOI: https://doi.org/10.1007/978-3-540-24749-4_44
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-21236-2
Online ISBN: 978-3-540-24749-4
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