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Related papers: Randomized selection revisited

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We show that several versions of Floyd and Rivest's algorithm Select for finding the $k$th smallest of $n$ elements require at most $n+\min\{k,n-k\}+o(n)$ comparisons on average and with high probability. This rectifies the analysis of…

Data Structures and Algorithms · Computer Science 2007-05-23 Krzysztof C. Kiwiel

We show that several versions of Floyd and Rivest's improved algorithm Select for finding the $k$th smallest of $n$ elements require at most $n+\min\{k,n-k\}+O(n^{1/2}\ln^{1/2}n)$ comparisons on average and with high probability. This…

Data Structures and Algorithms · Computer Science 2007-05-23 Krzysztof C. Kiwiel

We show that several versions of Floyd and Rivest's algorithm Select [Comm.\ ACM {\bf 18} (1975) 173] for finding the $k$th smallest of $n$ elements require at most $n+\min\{k,n-k\}+o(n)$ comparisons on average, even when equal elements…

Data Structures and Algorithms · Computer Science 2007-05-23 Krzysztof C. Kiwiel

Given $n$ elements, an integer $k$ and a parameter $\varepsilon$, we study to select an element with rank in $(k-n\varepsilon,k+n\varepsilon]$ using unreliable comparisons where the outcome of each comparison is incorrect independently with…

Data Structures and Algorithms · Computer Science 2022-05-04 Shengyu Huang , Chih-Hung Liu , Daniel Rutschman

We introduce a new model to study algorithm design under unreliable information, and apply this model for the problem of finding the uncorrupted maximum element of a list containing $n$ elements, among which are $k$ corrupted elements.…

Data Structures and Algorithms · Computer Science 2024-09-11 Trung Dang , Zhiyi Huang

In this paper we deal with the problem of finding the smallest and the largest elements of a totally ordered set of size $n$ using pairwise comparisons if $k$ of the comparisons might be erroneous where $k$ is a fixed constant. We prove…

Discrete Mathematics · Computer Science 2011-11-15 Dömötör Pálvölgyi

We consider the \emph{approximate minimum selection} problem in presence of \emph{independent random comparison faults}. This problem asks to select one of the smallest $k$ elements in a linearly-ordered collection of $n$ elements by only…

Data Structures and Algorithms · Computer Science 2020-07-08 Stefano Leucci , Chih-Hung Liu

An algorithm is presented that efficiently solves the selection problem: finding the k-th smallest member of a set. Relevant to a divide-and-conquer strategy, the algorithm also partitions a set into small and large valued subsets. Applied…

Data Structures and Algorithms · Computer Science 2007-05-23 Greg Sepesi

Given $n$ colored balls, we want to detect if more than $\lfloor n/2\rfloor$ of them have the same color, and if so find one ball with such majority color. We are only allowed to choose two balls and compare their colors, and the goal is to…

Data Structures and Algorithms · Computer Science 2016-05-02 Paweł Gawrychowski , Jukka Suomela , Przemysław Uznański

The selection problem, where one wishes to locate the $k^{th}$ smallest element in an unsorted array of size $n$, is one of the basic problems studied in computer science. The main focus of this work is designing algorithms for solving the…

Data Structures and Algorithms · Computer Science 2012-08-30 Tsvi Kopelowitz , Nimrod Talmon

We consider a multi-pivot QuickSort algorithm using $K\in\mathbb{N}$ pivot elements to partition a nonsorted list into $K+1$ sublists in order to proceed recursively on these sublists. For the partitioning stage, various strategies are in…

Probability · Mathematics 2026-05-01 Cecilia Holmgren , Jasper Ischebeck , Daniel Krenn , Florian Lesny , Ralph Neininger

In this paper, we present an ensemble algorithm for selection problem to find the k-th smallest element in the unsorted database. We will search the k-th smallest element by using "divide-and-conquer" strategy. We first divide D, the domain…

Quantum Physics · Physics 2007-05-23 Chien-Yuan Chen , Chih-Cheng Hsueh

When algorithms for sorting and searching are applied to keys that are represented as bit strings, we can quantify the performance of the algorithms not only in terms of the number of key comparisons required by the algorithms but also in…

Probability · Mathematics 2009-04-16 James Allen Fill , Take Nakama

We provide a smoothed analysis of Hoare's find algorithm and we revisit the smoothed analysis of quicksort. Hoare's find algorithm - often called quickselect - is an easy-to-implement algorithm for finding the k-th smallest element of a…

Data Structures and Algorithms · Computer Science 2009-04-27 Mahmoud Fouz , Manfred Kufleitner , Bodo Manthey , Nima Zeini Jahromi

We use soft heaps to obtain simpler optimal algorithms for selecting the $k$-th smallest item, and the set of~$k$ smallest items, from a heap-ordered tree, from a collection of sorted lists, and from $X+Y$, where $X$ and $Y$ are two…

Data Structures and Algorithms · Computer Science 2018-02-21 Haim Kaplan , László Kozma , Or Zamir , Uri Zwick

Given an unordered array of $N$ elements drawn from a totally ordered set and an integer $k$ in the range from $1$ to $N$, in the classic selection problem the task is to find the $k$-th smallest element in the array. We study the…

Data Structures and Algorithms · Computer Science 2014-07-15 Amr Elmasry , Daniel Dahl Juhl , Jyrki Katajainen , Srinivasa Rao Satti

Many combinatorial problems involve determining whether a universe of $n$ elements contains a witness consisting of $k$ elements which have some specified property. In this paper we investigate the relationship between the decision and…

Data Structures and Algorithms · Computer Science 2018-01-08 Kitty Meeks

We propose a new finding $k$-minima algorithm and prove that its query complexity is $\mathcal{O}(\sqrt{kN})$, where $N$ is the number of data indices. Though the complexity is equivalent to that of an existing method, the proposed is…

Quantum Physics · Physics 2019-07-09 Kohei Miyamoto , Masakazu Iwamura , Koichi Kise

We present new distributed algorithms for constructing a Steiner Forest in the CONGEST model. Our deterministic algorithm finds, for any given constant $\epsilon>0$, a $(2+\epsilon)$-approximation in $\tilde{O}(sk+\sqrt{\min(st,n)})$…

Distributed, Parallel, and Cluster Computing · Computer Science 2014-05-09 Christoph Lenzen , Boaz Patt-Shamir

In this note, we revisit the recursive random contraction algorithm of Karger and Stein for finding a minimum cut in a graph. Our revisit is occasioned by a paper of Fox, Panigrahi, and Zhang which gives an extension of the Karger-Stein…

Data Structures and Algorithms · Computer Science 2020-10-30 David R. Karger , David P. Williamson
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