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Computing cohesive subgraphs is a central problem in graph theory. While many formulations of cohesive subgraphs lead to NP-hard problems, finding a densest subgraph can be done in polynomial time. As such, the densest subgraph model has…

Data Structures and Algorithms · Computer Science 2021-11-24 Riccardo Dondi , Danny Hermelin

We study the complexity of approximating the permanent of a positive semidefinite matrix $A\in \mathbb{C}^{n\times n}$. 1. We design a new approximation algorithm for $\mathrm{per}(A)$ with approximation ratio $e^{(0.9999 + \gamma)n}$,…

Data Structures and Algorithms · Computer Science 2024-04-18 Farzam Ebrahimnejad , Ansh Nagda , Shayan Oveis Gharan

A natural requirement of many distributed structures is fault-tolerance: after some failures, whatever remains from the structure should still be effective for whatever remains from the network. In this paper we examine spanners of general…

Data Structures and Algorithms · Computer Science 2011-02-01 Michael Dinitz , Robert Krauthgamer

The matrix scaling problem, particularly the Sinkhorn-Knopp algorithm, has been studied for over 60 years. In practice, the algorithm often yields high-quality approximations within just a few iterations. Theoretically, however, the…

Data Structures and Algorithms · Computer Science 2025-08-12 Kun He

We consider the maximization problem in the value oracle model of functions defined on $k$-tuples of sets that are submodular in every orthant and $r$-wise monotone, where $k\geq 2$ and $1\leq r\leq k$. We give an analysis of a…

Data Structures and Algorithms · Computer Science 2016-08-05 Justin Ward , Stanislav Zivny

In this work, we study the hardness of approximation of the fair $k$-center problem. In this problem, we are given a set of data points in a metric space that is partitioned into groups and the task is to choose a subset of $k$-data points,…

Computational Complexity · Computer Science 2026-02-24 Suhas Thejaswi

For any given $\epsilon>0$ we provide an algorithm for the Densest $k$-Subhypergraph Problem with an approximation ratio of at most $O(n^{\theta_m+2\epsilon})$ for $\theta_m=\frac{1}{2}m-\frac{1}{2}-\frac{1}{2m}$ and run time at most…

Data Structures and Algorithms · Computer Science 2016-10-18 Richard Taylor

Let $\Phi = (V, \mathcal{C})$ be a constraint satisfaction problem on variables $v_1,\dots, v_n$ such that each constraint depends on at most $k$ variables and such that each variable assumes values in an alphabet of size at most $[q]$.…

Data Structures and Algorithms · Computer Science 2020-11-25 Vishesh Jain , Huy Tuan Pham , Thuy Duong Vuong

We analyze the so-called ppz algorithm for (d,k)-CSP problems for general values of d (number of values a variable can take) and k (number of literals per constraint). To analyze its success probability, we prove a correlation inequality…

Data Structures and Algorithms · Computer Science 2010-10-28 Dominik Scheder

We consider the problem of maximizing a monotone submodular function subject to a knapsack constraint. Our main contribution is an algorithm that achieves a nearly-optimal, $1 - 1/e - \epsilon$ approximation, using…

Data Structures and Algorithms · Computer Science 2018-11-20 Alina Ene , Huy L. Nguyen

If a two-player social welfare maximization problem does not admit a PTAS, we prove that any maximal-in-range truthful mechanism that runs in polynomial time cannot achieve an approximation factor better than 1/2. Moreover, for the k-player…

Computer Science and Game Theory · Computer Science 2009-12-18 Shaddin Dughmi , Hu Fu , Robert Kleinberg

It has long been known, since the classical work of (Arora, Karger, Karpinski, JCSS~99), that \MC\ admits a PTAS on dense graphs, and more generally, \kCSP\ admits a PTAS on "dense" instances with $\Omega(n^k)$ constraints. In this paper we…

Computational Complexity · Computer Science 2015-07-17 Dimitris Fotakis , Michael Lampis , Vangelis Th. Paschos

The 0/1 knapsack problem is weakly NP-hard in that there exist pseudo-polynomial time algorithms based on dynamic programming that can solve it exactly. There are also the core branch and bound algorithms that can solve large randomly…

Neural and Evolutionary Computing · Computer Science 2019-03-11 Shalin Shah

We study the problem of robustly estimating the parameter $p$ of an Erd\H{o}s-R\'enyi random graph on $n$ nodes, where a $\gamma$ fraction of nodes may be adversarially corrupted. After showing the deficiencies of canonical estimators, we…

Data Structures and Algorithms · Computer Science 2022-02-16 Jayadev Acharya , Ayush Jain , Gautam Kamath , Ananda Theertha Suresh , Huanyu Zhang

This work is concerned with the prime factor decomposition (PFD) of strong product graphs. A new quasi-linear time algorithm for the PFD with respect to the strong product for arbitrary, finite, connected, undirected graphs is derived.…

Discrete Mathematics · Computer Science 2017-05-11 Marc Hellmuth

We present several novel encodings for cardinality constraints, which use fewer clauses than previous encodings and, more importantly, introduce new generally applicable techniques for constructing compact encodings. First, we present a CNF…

Computational Complexity · Computer Science 2026-04-20 Andrew Krapivin , Benjamin Przybocki , Bernardo Subercaseaux

Model counting is a fundamental problem that consists of determining the number of satisfying assignments for a given Boolean formula. The weighted variant, which computes the weighted sum of satisfying assignments, has extensive…

Discrete Mathematics · Computer Science 2026-05-08 L. Sunil Chandran , Rishikesh Gajjala , Kuldeep S. Meel

We introduce two algorithms for computing tight guarantees on the probabilistic robustness of Bayesian Neural Networks (BNNs). Computing robustness guarantees for BNNs is a significantly more challenging task than verifying the robustness…

Machine Learning · Computer Science 2024-03-01 Ben Batten , Mehran Hosseini , Alessio Lomuscio

The sum of radii problem ($k$-MSR) asks, given a metric space on $n$ points, to place $k$ balls covering all points so as to minimize the sum of their radii. Despite extensive study from the perspectives of approximation and parameterized…

Data Structures and Algorithms · Computer Science 2026-05-08 Ameet Gadekar

We consider the weighted $k$-set packing problem, in which we are given a collection of weighted sets, each with at most $k$ elements and must return a collection of pairwise disjoint sets with maximum total weight. For $k = 3$, this…

Data Structures and Algorithms · Computer Science 2023-01-19 Theophile Thiery , Justin Ward