Skip to main content

Fragile Complexity of Adaptive Algorithms

  • Conference paper
  • First Online:
Algorithms and Complexity (CIAC 2021)

Abstract

The fragile complexity of a comparison-based algorithm is f(n) if each input element participates in O(f(n)) comparisons. In this paper, we explore the fragile complexity of algorithms adaptive to various restrictions on the input, i.e., algorithms with a fragile complexity parameterized by a quantity other than the input size n. We show that searching for the predecessor in a sorted array has fragile complexity \(\varTheta (\log k)\), where k is the rank of the query element, both in a randomized and a deterministic setting. For predecessor searches, we also show how to optimally reduce the amortized fragile complexity of the elements in the array. We also prove the following results: Selecting the kth smallest element has expected fragile complexity \(O(\log \log k)\) for the element selected. Deterministically finding the minimum element has fragile complexity \(\varTheta (\log (\mathrm {Inv}))\) and \(\varTheta (\log (\mathrm {Runs}))\), where \(\mathrm {Inv}\) is the number of inversions in a sequence and \(\mathrm {Runs}\) is the number of increasing runs in a sequence. Deterministically finding the median has fragile complexity \(O(\log (\mathrm {Runs}) + \log \log n)\) and \(\varTheta (\log (\mathrm {Inv}))\). Deterministic sorting has fragile complexity \(\varTheta (\log (\mathrm {Inv}))\) but it has fragile complexity \(\varTheta (\log n)\) regardless of the number of runs.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 64.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 84.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    For simplicity of exposition, we assume the rank is close to one, but the result clearly holds for rank distance to other positions in A.

  2. 2.

    The measure \(\mathrm {Inv}\) is defined as the total number of inversions in the input, where each of the \({n\atopwithdelims ()2}\) pairs of elements constitute an inversion if the elements of the pair appear in the wrong order. The measure \(\mathrm {Runs}\) is defined as the number of runs in the input, where a run is a maximal consecutive ascending subsequence.

References

  1. Afshani, P., et al.: Fragile complexity of comparison-based algorithms. In: Bender, M.A., Svensson, O., Herman, G. (eds.) 27th Annual European Symposium on Algorithms, ESA 2019, 9–11 September 2019, Munich/Garching, Germany. LIPIcs, vol. 144, pp. 2:1–2:19. Schloss Dagstuhl - Leibniz-Zentrum für Informatik (2019)

    Google Scholar 

  2. Ajtai, M., Komlós, J., Szemerédi, E.: An \(O(n \log n)\) sorting network. In: Proceedings of the 15th Symposium on Theory of Computation, STOC 1983, pp. 1–9. ACM (1983)

    Google Scholar 

  3. Ajtai, M., Komlós, J., Szemerédi, E.: Sorting in \(c \log n\) parallel steps. Combinatorica 3(1), 1–19 (1983)

    MathSciNet  MATH  Google Scholar 

  4. Alekseev, V.E.: Sorting algorithms with minimum memory. Kibernetika 5(5), 99–103 (1969)

    Google Scholar 

  5. Batcher, K.E.: Sorting networks and their applications. In: Proceedings of AFIPS Spring Joint Computer Conference, pp. 307–314 (1968)

    Google Scholar 

  6. Bose, P., Cano, P., Fagerberg, R., Iacono, J., Jacob, R., Langerman, S.: Fragile complexity of adaptive algorithms (2021). To appear in arXiv

    Google Scholar 

  7. Brodal, G.S., Pinotti, M.C.: Comparator networks for binary heap construction. In: Arnborg, S., Ivansson, L. (eds.) SWAT 1998. LNCS, vol. 1432, pp. 158–168. Springer, Heidelberg (1998). https://doi.org/10.1007/BFb0054364

    Chapter  Google Scholar 

  8. Bulánek, J., Koucký, M., Saks, M.E.: Tight lower bounds for the online labeling problem. SIAM J. Comput. 44(6), 1765–1797 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  9. Chvátal, V.: Lecture notes on the new AKS sorting network. Technical report DCS-TR-294, Department of Computer Science, Rutgers University, New Brunswick, NJ, October 1992

    Google Scholar 

  10. Dowd, M., Perl, Y., Rudolph, L., Saks, M.: The periodic balanced sorting network. J. ACM 36(4), 738–757 (1989)

    Article  MathSciNet  MATH  Google Scholar 

  11. Estivill-Castro, V., Wood, D.: A survey of adaptive sorting algorithms. ACM Comput. Surv. 24(4), 441–476 (1992)

    Article  Google Scholar 

  12. Fredman, M.L.: Two applications of a probabilistic search technique: sorting x + y and building balanced search trees. In: Rounds, W.C., Martin, N., Carlyle, J.W., Harrison, M.A. (eds.) Proceedings of the 7th Annual ACM Symposium on Theory of Computing, Albuquerque, New Mexico, USA, 5–7 May 1975, pp. 240–244. ACM (1975)

    Google Scholar 

  13. Goodrich, M.T.: Zig-zag sort: a simple deterministic data-oblivious sorting algorithm running in \(O(n \log n)\) time. In: Shmoys, D.B. (ed.) STOC 2014, pp. 684–693. ACM (2014)

    Google Scholar 

  14. Guibas, L.J., Sedgewick, R.: A dichromatic framework for balanced trees. In: 19th Annual Symposium on Foundations of Computer Science, Ann Arbor, Michigan, USA, 16–18 October 1978, pp. 8–21. IEEE Computer Society (1978)

    Google Scholar 

  15. Itai, A., Konheim, A.G., Rodeh, M.: A sparse table implementation of priority queues. In: Even, S., Kariv, O. (eds.) ICALP 1981. LNCS, vol. 115, pp. 417–431. Springer, Heidelberg (1981). https://doi.org/10.1007/3-540-10843-2_34

    Chapter  Google Scholar 

  16. Jimbo, S., Maruoka, A.: A method of constructing selection networks with \({O}(\log n)\) depth. SIAM J. Comput. 25(4), 709–739 (1996)

    MathSciNet  MATH  Google Scholar 

  17. Parberry, I.: The pairwise sorting network. Parallel Process. Lett. 2(2–3), 205–211 (1992)

    Article  MathSciNet  Google Scholar 

  18. Parker, B., Parberry, I.: Constructing sorting networks from \(k\)-sorters. Inf. Process. Lett. 33(3), 157–162 (1989)

    MathSciNet  MATH  Google Scholar 

  19. Paterson, M.S.: Improved sorting networks with \({O}(\log {N})\) depth. Algorithmica 5(1), 75–92 (1990)

    MathSciNet  MATH  Google Scholar 

  20. Pippenger, N.: Selection networks. SIAM J. Comput. 20(5), 878–887 (1991)

    Article  MathSciNet  MATH  Google Scholar 

  21. Pratt, V.R.: Shellsort and Sorting Networks. Outstanding Dissertations in the Computer Sciences, Garland Publishing, New York (1972)

    Google Scholar 

  22. Seiferas, J.I.: Sorting networks of logarithmic depth, further simplified. Algorithmica 53(3), 374–384 (2009)

    Article  MathSciNet  MATH  Google Scholar 

  23. Hoory, S., Linial, N., Wigderson, A.: Expander graphs and their applications. BAMS Bull. Am. Math. Soc. 43, 439–561 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  24. Vadhan, S.P.: Pseudorandomness. Found. Trends Theoret. Comput. Sci. 7(1–3), 1–336 (2012)

    Article  MathSciNet  MATH  Google Scholar 

  25. Willard, D.E.: Good worst-case algorithms for inserting and deleting records in dense sequential files. In: Zaniolo, C. (ed.) Proceedings of the 1986 ACM SIGMOD International Conference on Management of Data, Washington, DC, USA, 28–30 May 1986, pp. 251–260. ACM Press (1986)

    Google Scholar 

  26. Willard, D.E.: A density control algorithm for doing insertions and deletions in a sequentially ordered file in good worst-case time. Inf. Comput. 97(2), 150–204 (1992)

    Article  MATH  Google Scholar 

  27. Yao, A., Yao, F.F.: Lower bounds on merging networks. J. ACM 23(3), 566–571 (1976)

    Article  MathSciNet  MATH  Google Scholar 

Download references

Acknowledgements

This material is based upon work performed while attending AlgoPARC Workshop on Parallel Algorithms and Data Structures at the University of Hawaii at Manoa, in part supported by the National Science Foundation under Grant No. CCF-1930579. We thank Timothy Chan and Qizheng He for their ideas improving the randomized selection algorithm.

P.B was partially supported by NSERC. P.C and J.I. were supported by F.R.S.-FNRS under Grant no MISU F 6001 1. R.F. was partially supported by the Independent Research Fund Denmark, Natural Sciences, grant DFF-7014-00041. J.I. was supported by NSF grant CCF-1533564. S.L. is Directeur de Recherches du F.R.S.-FNRS.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Pilar Cano .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2021 Springer Nature Switzerland AG

About this paper

Check for updates. Verify currency and authenticity via CrossMark

Cite this paper

Bose, P., Cano, P., Fagerberg, R., Iacono, J., Jacob, R., Langerman, S. (2021). Fragile Complexity of Adaptive Algorithms. In: Calamoneri, T., Corò, F. (eds) Algorithms and Complexity. CIAC 2021. Lecture Notes in Computer Science(), vol 12701. Springer, Cham. https://doi.org/10.1007/978-3-030-75242-2_10

Download citation

  • DOI: https://doi.org/10.1007/978-3-030-75242-2_10

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-75241-5

  • Online ISBN: 978-3-030-75242-2

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics