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Related papers: Tight Bounds for Online Stable Sorting

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It is a long-standing open question to determine the minimum number of comparisons $S(n)$ that suffice to sort an array of $n$ elements. Indeed, before this work $S(n)$ has been known only for $n\leq 22$ with the exception for $n=16$, $17$,…

Data Structures and Algorithms · Computer Science 2022-11-21 Florian Stober , Armin Weiß

Sorting is a fundamental problem in computer science. In the classical setting, it is well-known that $(1\pm o(1)) n\log_2 n$ comparisons are both necessary and sufficient to sort a list of $n$ elements. In this paper, we study the Noisy…

Data Structures and Algorithms · Computer Science 2023-03-16 Yuzhou Gu , Yinzhan Xu

We consider the online bin packing problem under the advice complexity model where the 'online constraint' is relaxed and an algorithm receives partial information about the future requests. We provide tight upper and lower bounds for the…

Data Structures and Algorithms · Computer Science 2013-12-24 Joan Boyar , Shahin Kamali , Kim S. Larsen , Alejandro López-Ortiz

The problem of online checkpointing is a classical problem with numerous applications which had been studied in various forms for almost 50 years. In the simplest version of this problem, a user has to maintain $k$ memorized checkpoints…

Cryptography and Security · Computer Science 2019-06-20 Achiya Bar-On , Itai Dinur , Orr Dunkelman , Rani Hod , Nathan Keller , Eyal Ronen , Adi Shamir

The following online bin packing problem is considered: Items with integer sizes are given and variable sized bins arrive online. A bin must be used if there is still an item remaining which fits in it when the bin arrives. The goal is to…

Data Structures and Algorithms · Computer Science 2018-06-05 Joan Boyar , Faith Ellen

We present the first in-place algorithm for sorting an array of size n that performs, in the worst case, at most O(n log n) element comparisons and O(n) element transports. This solves a long-standing open problem, stated explicitly, e.g.,…

Data Structures and Algorithms · Computer Science 2007-05-23 Gianni Franceschini , Viliam Geffert

In the online hypergraph matching problem, hyperedges of size $k$ over a common ground set arrive online in adversarial order. The goal is to obtain a maximum matching (disjoint set of hyperedges). A na\"ive greedy algorithm for this…

Data Structures and Algorithms · Computer Science 2024-02-15 Thorben Tröbst , Rajan Udwani

Sorting is the task of ordering $n$ elements using pairwise comparisons. It is well known that $m=\Theta(n\log n)$ comparisons are both necessary and sufficient when the outcomes of the comparisons are observed with no noise. In this paper,…

Information Theory · Computer Science 2024-07-09 Ziao Wang , Nadim Ghaddar , Banghua Zhu , Lele Wang

We consider the quantum complexities of the following three problems: searching an ordered list, sorting an un-ordered list, and deciding whether the numbers in a list are all distinct. Letting N be the number of elements in the input list,…

Quantum Physics · Physics 2016-12-30 Peter Hoyer , Jan Neerbek , Yaoyun Shi

A growing line of work shows how learned predictions can be used to break through worst-case barriers to improve the running time of an algorithm. However, incorporating predictions into data structures with strong theoretical guarantees…

Data Structures and Algorithms · Computer Science 2023-06-21 Samuel McCauley , Benjamin Moseley , Aidin Niaparast , Shikha Singh

We prove that any exact quantum algorithm searching an ordered list of N elements requires more than \frac{1}{\pi}(\ln(N)-1) queries to the list. This improves upon the previously best known lower bound of {1/12}\log_2(N) - O(1). Our proof…

Quantum Physics · Physics 2007-05-23 Peter Hoyer , Jan Neerbek

We improve the upper bound for the maximum possible number of stable matchings among $n$ jobs and $n$ applicants from $131072^n+O(1)$ to $3.55^n+O(1)$. To establish this bound, we state a novel formulation of a certain entropy bound that is…

Combinatorics · Mathematics 2021-06-07 Cory Palmer , Dömötör Pálvölgyi

In the Online List Labeling problem, a set of $n \leq N$ elements from a totally ordered universe must be stored in sorted order in an array with $m=N+\lceil\varepsilon N \rceil$ slots, where $\varepsilon \in (0,1]$ is constant, while an…

Data Structures and Algorithms · Computer Science 2024-05-08 Martin P. Seybold

We study the classic set cover problem from the perspective of sub-linear algorithms. Given access to a collection of $m$ sets over $n$ elements in the query model, we show that sub-linear algorithms derived from existing techniques have…

Data Structures and Algorithms · Computer Science 2019-02-12 Piotr Indyk , Sepideh Mahabadi , Ronitt Rubinfeld , Ali Vakilian , Anak Yodpinyanee

One of the fundamental problem in the theory of sorting is to find the pessimistic number of comparisons sufficient to sort a given number of elements. Currently 16 is the lowest number of elements for which we do not know the exact value.…

Data Structures and Algorithms · Computer Science 2015-03-17 Marcin Peczarski

In the online labeling problem with parameters n and m we are presented with a sequence of n keys from a totally ordered universe U and must assign each arriving key a label from the label set {1,2,...,m} so that the order of labels…

Data Structures and Algorithms · Computer Science 2012-10-12 Martin Babka , Jan Bulánek , Vladimír Čunát , Michal Koucký , Michael Saks

We consider the online $k$-median clustering problem in which $n$ points arrive online and must be irrevocably assigned to a cluster on arrival. As there are lower bound instances that show that an online algorithm cannot achieve a…

Data Structures and Algorithms · Computer Science 2023-03-28 Benjamin Moseley , Heather Newman , Kirk Pruhs

Consider an infinite sequence of independent, uniformly chosen points from $[0,1]^d$. After looking at each point in the sequence, an overseer is allowed to either keep it or reject it, and this choice may depend on the locations of all…

Probability · Mathematics 2017-09-05 Raaz Dwivedi , Ohad N. Feldheim , Ori Gurel-Gurevich , Aaditya Ramdas

We consider the problem of hitting sets online. The hypergraph (i.e., range-space consisting of points and ranges) is known in advance, and the ranges to be stabbed are input one-by-one in an online fashion. The online algorithm must stab…

Data Structures and Algorithms · Computer Science 2012-07-12 Guy Even , Shakhar Smorodinsky

We give a polynomial-time algorithm for OnlineSetCover with a competitive ratio of $O(\log mn)$ when the elements are revealed in random order, essentially matching the best possible offline bound of $O(\log n)$ and circumventing the…

Data Structures and Algorithms · Computer Science 2024-07-09 Anupam Gupta , Gregory Kehne , Roie Levin