Filters








81 Hits in 2.3 sec

Analysis of Hoare's FIND algorithm with Median-of-three partition

P. Kirschenhofer, H. Prodinger, C. Mart�nez
1997 Random structures & algorithms (Print)  
Hoare's FIND algorithm can be used to select the jth element out of a file of n elements.  ...  In this paper, we consider the Median-ofthree version, where the pivot element is chosen as the median of a random sample of three elements.  ...  The a¨erage number of passes to select the j th element out of a random permutation of n elements using Hoare's FIND algorithm with Median-of-three partition is 24 18 18 12 12 P s H q H q H q  ... 
doi:10.1002/(sici)1098-2418(199701/03)10:1/2<143::aid-rsa7>3.0.co;2-v fatcat:y3rpzxvm3vdkhfb4mzto2yaeki

On Smoothed Analysis of Quicksort and Hoare's Find

Mahmoud Fouz, Manfred Kufleitner, Bodo Manthey, Nima Zeini Jahromi
2011 Algorithmica  
We provide a smoothed analysis of Hoare's find algorithm and we revisit the smoothed analysis of quicksort.  ...  Finally, we provide lower bounds for the smoothed number of comparisons of quicksort and Hoare's find for the median-of-three pivot rule, which usually yields faster algorithms than always selecting the  ...  Scan Maxima with Median-of-three Rule The results in this section serve as a basis for the analysis of both quicksort and Hoare's find with the median-of-three rule.  ... 
doi:10.1007/s00453-011-9490-9 fatcat:hxbm3ibofbah7lanvkbq65euui

On Smoothed Analysis of Quicksort and Hoare's Find [chapter]

Mahmoud Fouz, Manfred Kufleitner, Bodo Manthey, Nima Zeini Jahromi
2009 Lecture Notes in Computer Science  
We provide a smoothed analysis of Hoare's find algorithm and we revisit the smoothed analysis of quicksort.  ...  Finally, we provide lower bounds for the smoothed number of comparisons of quicksort and Hoare's find for the median-of-three pivot rule, which usually yields faster algorithms than always selecting the  ...  Scan Maxima with Median-of-three Rule The results in this section serve as a basis for the analysis of both quicksort and Hoare's find with the median-of-three rule.  ... 
doi:10.1007/978-3-642-02882-3_17 fatcat:2xkl2nkdyvaqnb6choq25cmeja

Simple and Fast BlockQuicksort using Lomuto's Partitioning Scheme [article]

Martin Aumüller, Nikolaj Hass
2018 arXiv   pre-print
The simplification is achieved by using Lomuto's partitioning scheme instead of Hoare's crossing pointer technique to partition the input.  ...  The paper provides an analysis of the theoretical properties of the proposed algorithms and compares them to their competitors.  ...  Furthermore, we thank the anonymous reviewers for their suggestions that helped us in improving the presentation of this paper.  ... 
arXiv:1810.12047v1 fatcat:ucoyedclabc2pgaxiigzeiyl3y

Introspective Sorting and Selection Algorithms

DAVID R. MUSSER
1997 Software, Practice & Experience  
A similar dilemma exists with selection algorithms (for finding the i-th largest element) based on partitioning.  ...  For selection, a hybrid of Hoare's FIND algorithm, which is linear on average but quadratic in the worst case, and the Blum-Floyd-Pratt-Rivest-Tarjan algorithm is as fast as Hoare's algorithm in practice  ...  Stewart suggested the idea for the class of sequences K N . J. Valois and two anonymous referees made many useful comments on an earlier draft of this paper.  ... 
doi:10.1002/(sici)1097-024x(199708)27:8<983::aid-spe117>3.0.co;2-# fatcat:ry3jci2xfrfqbem5qbau7amxbu

Page 6546 of Mathematical Reviews Vol. , Issue 2000i [page]

2000 Mathematical Reviews  
Hoare’s classic recursive FIND algorithm [Comm. ACM 4 (1961), 321-322] to locate the /th smallest element of a set S of cardinality n, a random partitioning element x is first chosen from the set S.  ...  {For the entire collection see MR 2000h:68007. } 20001:68036 68P10 68Q25 Griibel, Rudolf (D-HANN-IMS; Hannover) On the median-of-k version of Hoare’s selection algorithm. (English summary) Theor.  ... 

Page 2049 of Mathematical Reviews Vol. , Issue 99c [page]

1991 Mathematical Reviews  
|Martinez, Conrado] (E-UPB-LI; Barcelona) Analysis of Hoare’s FIND algorithm with median-of-three partition. (English summary) Average-case analysis of algorithms (Dagstuhl, 1995).  ...  This article presents some results concerning the average number of passes and comparisons in Hoare’s Find algorithm in the case where the pivot element is the median of a random sample of three elements  ... 

Page 7265 of Mathematical Reviews Vol. , Issue 98K [page]

1998 Mathematical Reviews  
Martinez [Conrado Martinez], Anal- ysis of Hoare’s FIND algorithm with median-of-three partition (143-156); Guy Louchard, Probabilistic analysis of adaptative sampling (157-168); Hosam M.  ...  {Some of the papers are being reviewed individually. } 98k:68003 68-06 68025 * Average-case analysis of algorithms.  ... 

Theory and Implementation of Online Multiselection Algorithms [chapter]

Jérémy Barbay, Ankur Gupta, Seungbum Jo, Satti Srinivasa Rao, Jonathan Sorenson
2013 Lecture Notes in Computer Science  
We show that our online algorithm is 1-competitive in terms of data comparisons.  ...  We introduce a new online algorithm for the multiselection problem which performs a sequence of selection queries on a given unsorted array.  ...  Lemma 4 . 4 The number of comparisons required to find the median of medians and partition over all nodes v in the pivot tree T with at least 4 2 elements is within o(B(S t )) + O(n).  ... 
doi:10.1007/978-3-642-40450-4_10 fatcat:wsib4ffh6jggfohha7gtqyccym

On the median-of-k version of Hoare's selection algorithm

Rudolf Grübel
1999 RAIRO - Theoretical Informatics and Applications  
A detailed analysis of the number of comparisons for k = 1 is given in Anderson and Brown [1] , who mention a renewed interest in median-of-three sélection.  ...  For the median-of-three version of FIND we have the following explicit result. Theorem 3 . 3 mi(t) = 2 + 3t(l -t) for all t e [0,1].  ... 
doi:10.1051/ita:1999112 fatcat:4b4nl452vffanbda3ewhgt6kgu

BlockQuicksort: How Branch Mispredictions don't affect Quicksort [article]

Stefan Edelkamp, Armin Weiß
2016 arXiv   pre-print
elements); then, all elements in one block are compared with the pivot and the outcomes of the comparisons are stored in a buffer.  ...  Since the work of Kaligosi and Sanders (2006), it is well-known that Quicksort -- which is commonly considered as one of the fastest in-place sorting algorithms -- suffers in an essential way from branch  ...  We are also indebted to Jan Philipp Wächter for all his help with creating the plots, to Daniel Bahrdt for answering many C++ questions, and to Christoph Greulich for his help with the experiments.  ... 
arXiv:1604.06697v2 fatcat:3xg63b7jqbfetcotcf6ws5xsfe

A two-pass exact algorithm for selection on Parallel Disk Systems

Tian Mi, Sanguthevar Rajasekaran
2013 2013 IEEE Symposium on Computers and Communications (ISCC)  
Our analysis shows that DSS is a (2 + ε)-pass algorithm when the total number of input elements N is a polynomial in the memory size M (i.e., N = M c for some constant c).  ...  Numerous OLAP queries process selection operations of "top N", median, "top 5%", in data warehousing applications.  ...  The selection problem is to identify the i th smallest element from out of N given input elements. In particular, finding the median has various applications in data analysis.  ... 
doi:10.1109/iscc.2013.6755015 pmid:25374478 pmcid:PMC4217089 dblp:conf/iscc/MiR13 fatcat:zxxoauobrndhpbcb5lm6jt5y7a

Analysis of Quickselect Under Yaroslavskiy's Dual-Pivoting Algorithm

Sebastian Wild, Markus E. Nebel, Hosam Mahmoud
2014 Algorithmica  
We investigate the number of comparisons made by Quickselect to find a key with a randomly selected rank under Yaroslavskiy's algorithm.  ...  There is excitement within the algorithms community about a new partitioning method introduced by Yaroslavskiy.  ...  The one-sided version (Quickselect) of the algorithm can be used to find order statistics. It is also known as Hoare's "Find" algorithm, which was first given in [15] .  ... 
doi:10.1007/s00453-014-9953-x fatcat:56nj7h2bkfcmdeygozivnmdil4

Fast Multidimensional Entropy Estimation by $k$-d Partitioning

Dan Stowell, Mark D. Plumbley
2009 IEEE Signal Processing Letters  
The estimator uses an adaptive partitioning method and runs in Θ N log N time, with low memory requirements.  ...  We describe a non-parametric estimator for the differential entropy of a multidimensional distribution, given a limited set of data points, by a recursive rectilinear partitioning.  ...  For our algorithm, the time complexity is dominated by the median partitioning, which we perform in Θ N time using Hoare's method [22] .  ... 
doi:10.1109/lsp.2009.2017346 fatcat:ubylrtowtzgkhahsgdn4d5bdvy

Knowledge-based clustering of ship trajectories using density-based approach

Bo Liu, Erico N. de Souza, Stan Matwin, Marcin Sydow
2014 2014 IEEE International Conference on Big Data (Big Data)  
While there is a large amount of data with variable quality, decision makers need reliable information about possible situations or threats.  ...  The main result of clustering is a set of generated lanes that can be mapped to those defined in the IMO directives.  ...  ACKNOWLEDGMENT The authors acknowledge the generous support of GSTS, Inc., ExactEarth, Inc. and the Natural Science and Engineering Research Council of Canada for this research.  ... 
doi:10.1109/bigdata.2014.7004281 dblp:conf/bigdataconf/LiuSMS14 fatcat:obaimaagjfcybfbwlyvoiglatu
« Previous Showing results 1 — 15 out of 81 results