Abstract
In Skip list data structure, linked lists are used. Nodes are allocated to different levels as linked list. By the help of these levels operations like item search, insertion, or removal can be performed easily (O(lg N)). However, in this data structure in the operation of adding nodes to levels, higher levels can be produced than needed. Creating higher levels affects the performance of this data structure negatively. In this article how randomly creation of levels and different “p” thresholds (0.1, 0.25, 0.5, 0.75, 0.9) affect the performance is studied and solutions are proposed. The problem of creating higher levels in Skip list data structure is solved by introducing optimum p thresholds. Hence, ideal p threshold levels are created for Skip list data structure
References
- Pugh W. 1990. Skip Lists: A Probabilistic Alternative to Balanced Trees, Communications of the ACM. 33(6): 668–676.
- Pugh W. 1989. A Skip List Cookbook, Dept. of Computer Science, University of Maryland, College Park, UMIACS–TR–89–72.1.
- Pugh W. 1989. Concurrent Maintenance of Skip Lists, Dept. of Computer Science, University of Maryland, College Park, TR–2222
- Aksu M., Karcı A., Yılmaz Ş. 2013. Skip List veri yapısında Seviye Optimizasyonu, ISITIES2013 (1st Internatıonal Symposıum on Innovatıve Technologıes ın Engıneerıng and Scıence), pp389-396.
- Herlihy M., Lev Y., Luchangco V., Shavit N. 2007. A Simple Optimistic Skiplist Algorithm, SIROCCO, pp124-138.
- Colvin R., Groves L., Luchangco V., Moir M. 2006 Formal veriŞcation of a lazy concurrent list- based set. In Proceedings of Computer-Aided VeriŞcation.
- Vyukov D., 2010. Concurrent Skip List. http://software.intel.com/sites/default/files/d6/31/33084 (Erişim Tarihi: 16.01.2014)
- Kirschenhofer P., Martinez C., Prodinger H. 1995. Analysis of an optimized search algorithm for skip lists, Theoretical Computer Science 144:199-220.
- Devroye L. 1992. A limit theory for random skip lists, Annals of Applied Probability, 2(3):597– 609.
- Kirschenhofer P., Prodinger H. 1994. The path length of random skip lists, Acta Informatica, 31(8):775–792.
- Papadakis T. 1993. Skip lists and probabilistic analysis of algorithms, Ph.D. Thesis, University of Waterloo, Tech. Report CS-93-28.
- Papadakis T., Munro J.I., Poblete P.V. 1992. Average search and update costs in skip lists, BIT 32:316–332.
- Poblete P.V., Munro J.I., Papadakis T. 2006. The binomial transform and the analysis of skip lists, Theoretical Computer Science 352:136 –158.
Abstract
Skip list veri yapısında bağlı listeler kullanılır. Düğümler, birbirine bağlı listeler halinde farklı seviyelere yerleştirilir. Bu seviyeler sayesinde eleman arama, ekleme, silme gibi işlemler kolayca (O(lg N)) yapılabilir. Bununla birlikte, bu veri yapısında seviyelere düğüm ekleme işleminde olması gerekenden yüksek seviyeler üretilebilmektedir. Yüksek seviyeler üretilmesi bu veri yapısının performansını olumsuz etkilemektedir. Bu makalede rastgele seviye üretme problemi ele alınarak farklı “p” eşik değerlerinin (0.1, 0.25, 0.5, 0.75, 0.9 gibi) performansı nasıl etkilediği ele alınıp çözüm önerilmiştir. Skip list veri yapısındaki yüksek seviye üretme problemi optimum p eşik değeri bulunarak çözülmüştür. Böylece, Skip list veri yapısı için p eşik değerlerine bağlı olarak ideal seviyeler oluşturulmuştur.
References
- Pugh W. 1990. Skip Lists: A Probabilistic Alternative to Balanced Trees, Communications of the ACM. 33(6): 668–676.
- Pugh W. 1989. A Skip List Cookbook, Dept. of Computer Science, University of Maryland, College Park, UMIACS–TR–89–72.1.
- Pugh W. 1989. Concurrent Maintenance of Skip Lists, Dept. of Computer Science, University of Maryland, College Park, TR–2222
- Aksu M., Karcı A., Yılmaz Ş. 2013. Skip List veri yapısında Seviye Optimizasyonu, ISITIES2013 (1st Internatıonal Symposıum on Innovatıve Technologıes ın Engıneerıng and Scıence), pp389-396.
- Herlihy M., Lev Y., Luchangco V., Shavit N. 2007. A Simple Optimistic Skiplist Algorithm, SIROCCO, pp124-138.
- Colvin R., Groves L., Luchangco V., Moir M. 2006 Formal veriŞcation of a lazy concurrent list- based set. In Proceedings of Computer-Aided VeriŞcation.
- Vyukov D., 2010. Concurrent Skip List. http://software.intel.com/sites/default/files/d6/31/33084 (Erişim Tarihi: 16.01.2014)
- Kirschenhofer P., Martinez C., Prodinger H. 1995. Analysis of an optimized search algorithm for skip lists, Theoretical Computer Science 144:199-220.
- Devroye L. 1992. A limit theory for random skip lists, Annals of Applied Probability, 2(3):597– 609.
- Kirschenhofer P., Prodinger H. 1994. The path length of random skip lists, Acta Informatica, 31(8):775–792.
- Papadakis T. 1993. Skip lists and probabilistic analysis of algorithms, Ph.D. Thesis, University of Waterloo, Tech. Report CS-93-28.
- Papadakis T., Munro J.I., Poblete P.V. 1992. Average search and update costs in skip lists, BIT 32:316–332.
- Poblete P.V., Munro J.I., Papadakis T. 2006. The binomial transform and the analysis of skip lists, Theoretical Computer Science 352:136 –158.
Details
| Primary Language | Turkish |
|---|---|
| Journal Section | Articles |
| Authors | |
| Publication Date | December 1, 2013 |
| Submission Date | January 5, 2015 |
| Published in Issue | Year 2013 Volume: 2 Issue: 2 |