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For many hard computational problems, simple algorithms that run in time $2^n \cdot n^{O(1)}$ arise, say, from enumerating all subsets of a size-$n$ set. Finding (exponentially) faster algorithms is a natural goal that has driven much of…

Data Structures and Algorithms · Computer Science 2025-06-30 László Kozma , Junqi Tan

We consider a variety of NP-Complete network connectivity problems. We introduce a novel dual-based approach to approximating network design problems with cut-based linear programming relaxations. This approach gives a $3/2$-approximation…

Data Structures and Algorithms · Computer Science 2017-07-24 Benjamin Grimmer

A tree $t$-spanner of a graph $G$ is a spanning tree of $G$ such that the distance between pairs of vertices in the tree is at most $t$ times their distance in $G$. Deciding tree $t$-spanner admissible graphs has been proved to be tractable…

Discrete Mathematics · Computer Science 2018-01-01 Ioannis Papoutsakis

This paper investigates the complexity of finding secluded paths in graphs. We focus on the \textsc{Short Secluded Path} problem and a natural new variant we introduce, \textsc{Shortest Secluded Path}. Formally, given an undirected graph…

Data Structures and Algorithms · Computer Science 2026-04-07 Tesshu Hanaka , Daisuke Tsuru

A tree $t$-spanner $T$ of a graph $G$ is a spanning tree of $G$ such that the distance in $T$ between every pair of verices is at most $t$ times the distance in $G$ between them. There are efficient algorithms that find a tree $t\cdot…

Computational Complexity · Computer Science 2016-04-19 Ioannis Papoutsakis

Graph mining analyzes real-world graphs to find core substructures (connected subgraphs) in applications modeled as graphs. Substructure discovery is a process that involves identifying meaningful patterns, structures, or components within…

Social and Information Networks · Computer Science 2025-04-29 Arshdeep Singh , Abhishek Santra , Sharma Chakravarthy

Given an undirected graph $G$, the problem of deciding whether $G$ admits a simple and proper time-labeling that makes it temporally connected is known to be NP-hard (G\"obel et al., 1991). In this article, we relax this problem and ask…

Data Structures and Algorithms · Computer Science 2026-05-06 Arnaud Casteigts , Michelle Döring , Nils Morawietz

A $t$-spanner of a graph is a subgraph that $t$-approximates pairwise distances. The greedy algorithm is one of the simplest and most well-studied algorithms for constructing a sparse spanner: it computes a $t$-spanner with $n^{1+O(1/t)}$…

Data Structures and Algorithms · Computer Science 2023-08-03 Bernhard Haeupler , D Ellis Hershkowitz , Zihan Tan

In this paper, we prove that for every connected graph G, there exists a split graph H with the same independence number and the same order. Then we propose a first algorithm for finding this graph, given the degree sequence of the input…

Discrete Mathematics · Computer Science 2008-01-09 Omar Kettani

Given an undirected, unweighted graph with $n$ vertices and $m$ edges, the maximum cut problem is to find a partition of the $n$ vertices into disjoint subsets $V_1$ and $V_2$ such that the number of edges between them is as large as…

We introduce two quantum algorithms for solving structured prediction problems. We first show that a stochastic gradient descent that uses the quantum minimum finding algorithm and takes its probabilistic failure into account solves the…

Machine Learning · Computer Science 2021-07-05 Behrooz Sepehry , Ehsan Iranmanesh , Michael P. Friedlander , Pooya Ronagh

We study the problem of finding a small sparse cut in an undirected graph. Given an undirected graph G=(V,E) and a parameter k <= |E|, the small sparsest cut problem is to find a subset of vertices S with minimum conductance among all sets…

Data Structures and Algorithms · Computer Science 2012-04-23 Tsz Chiu Kwok , Lap Chi Lau

Given a point set $P$ in the Euclidean space, a geometric $t$-spanner $G$ is a graph on $P$ such that for every pair of points, the shortest path in $G$ between those points is at most a factor $t$ longer than the Euclidean distance between…

Computational Geometry · Computer Science 2024-12-10 Kevin Buchin , Carolin Rehs , Torben Scheele

The K-way vertex cut problem} consists in, given a graph G, finding a subset of vertices of a given size, whose removal partitions G into the maximum number of connected components. This problem has many applications in several areas. It…

Computational Complexity · Computer Science 2021-12-06 Mohammed Lalou

Let $G$ be a strongly connected directed graph. We consider the following three problems, where we wish to compute the smallest strongly connected spanning subgraph of $G$ that maintains respectively: the $2$-edge-connected blocks of $G$…

Data Structures and Algorithms · Computer Science 2015-09-10 Loukas Georgiadis , Giuseppe F. Italiano , Charis Papadopoulos , Nikos Parotsidis

We study graph partitioning problems from a min-max perspective, in which an input graph on n vertices should be partitioned into k parts, and the objective is to minimize the maximum number of edges leaving a single part. The two main…

Data Structures and Algorithms · Computer Science 2011-10-21 Nikhil Bansal , Uriel Feige , Robert Krauthgamer , Konstantin Makarychev , Viswanath Nagarajan , Joseph , Naor , Roy Schwartz

Span programs characterize the quantum query complexity of binary functions $f:\{0,\ldots,\ell\}^n \to \{0,1\}$ up to a constant factor. In this paper we generalize the notion of span programs for functions with non-binary input/output…

Quantum Physics · Physics 2019-05-31 Salman Beigi , Leila Taghavi

We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are…

Quantum Physics · Physics 2015-05-14 Mark Hillery , Daniel Reitzner , Vladimir Buzek

Consider a setting where possibly sensitive information sent over a path in a network is visible to every {neighbor} of the path, i.e., every neighbor of some node on the path, thus including the nodes on the path itself. The exposure of a…

Data Structures and Algorithms · Computer Science 2012-12-27 Shiri Chechik , M. P. Johnson , Merav Parter , David Peleg

The directed graph reachability problem takes as input an $n$-vertex directed graph $G=(V,E)$, and two distinguished vertices $s$ and $t$. The problem is to determine whether there exists a path from $s$ to $t$ in $G$. This is a canonical…

Data Structures and Algorithms · Computer Science 2019-09-23 Ryo Ashida , Kotaro Nakagawa