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We provide a remarkably simple algorithm to compute all (at most four) common tangents of two disjoint simple polygons. Given each polygon as a read-only array of its corners in cyclic order, the algorithm runs in linear time and constant…

Computational Geometry · Computer Science 2018-12-11 Mikkel Abrahamsen , Bartosz Walczak

Convex hull data structures are fundamental in computational geometry. We study insertion-only data structures, supporting various containment and intersection queries. When $P$ is sorted by $x$- or $y$-coordinate, convex hulls can be…

Computational Geometry · Computer Science 2025-08-26 Ivor van der Hoog , Henrik Reinstädtler , Eva Rotenberg

This study presents a novel algorithm for identifying the set of extreme points that constitute the exact convex hull of a point set in high-dimensional Euclidean space. The proposed method iteratively solves a sequence of dynamically…

Computational Geometry · Computer Science 2025-11-11 Qianwei Zhuang

Separable convex optimization problems with linear ascending inequality and equality constraints are addressed in this paper. Under an ordering condition on the slopes of the functions at the origin, an algorithm that determines the optimum…

Information Theory · Computer Science 2011-07-22 Arun Padakandla , Rajesh Sundaresan

Let $P$ be a set of $n$ points in $\mathbb{R}^2$. For a given positive integer $w<n$, our objective is to find a set $C \subset P$ of points, such that $CH(P\setminus C)$ has the smallest number of vertices and $C$ has at most $n-w$ points.…

Computational Geometry · Computer Science 2021-03-03 Vahideh Keikha

We present two parallel optimization algorithms for a convex function $f$. The first algorithm optimizes over linear inequality constraints in a Hilbert space, $\mathbb H$, and the second over a non convex polyhedron in $\mathbb R^n$. The…

Optimization and Control · Mathematics 2025-10-22 E. Dov Neimand , Serban Sabau

Let $P$ be a planar set of $n$ points in general position. We consider the problem of computing an orientation of the plane for which the Rectilinear Convex Hull of $P$ has minimum area. Bae et al. (Computational Geometry: Theory and…

Computational Geometry · Computer Science 2017-12-29 Carlos Alegría-Galicia , Tzolkin Garduño , Carlos Seara , Areli Rosas-Navarrete , Jorge Urrutia

Given a finite set of points $P \subseteq \mathbb{R}^d$, we would like to find a small subset $S \subseteq P$ such that the convex hull of $S$ approximately contains $P$. More formally, every point in $P$ is within distance $\epsilon$ from…

Computational Geometry · Computer Science 2017-12-15 Avrim Blum , Vladimir Braverman , Ananya Kumar , Harry Lang , Lin F. Yang

Solving linear programs is often a challenging task in distributed settings. While there are good algorithms for solving packing and covering linear programs in a distributed manner (Kuhn et al.~2006), this is essentially the only class of…

Data Structures and Algorithms · Computer Science 2017-09-12 Michael Dinitz , Yasamin Nazari

For a planar point set $P$, its convex hull is the smallest convex polygon that encloses all points in $P$. The construction of the convex hull from an array $I_P$ containing $P$ is a fundamental problem in computational geometry. By…

Computational Geometry · Computer Science 2025-06-30 Ivor van der Hoog , Eva Rotenberg , Daniel Rutschmann

Let $P$ be a simple polygon of $n$ vertices. We consider two-point $L_1$ shortest path queries in $P$. We build a data structure of $O(n)$ size in $O(n)$ time such that given any two query points $s$ and $t$, the length of an $L_1$ shortest…

Computational Geometry · Computer Science 2018-09-21 Sang Won Bae , Haitao Wang

We consider the set of points chosen randomly, independently and uniformly in the $d$-dimensional spherical layer. A set of points is called $1$-convex if all its points are vertices of the convex hull of this set. In \cite{3} an estimate…

Combinatorics · Mathematics 2018-06-14 Sergey Sidorov

Given a point $s$ and a set of $h$ pairwise disjoint polygonal obstacles of totally $n$ vertices in the plane, we present a new algorithm for building an $L_1$ shortest path map of size O(n) in $O(T)$ time and O(n) space such that for any…

Computational Geometry · Computer Science 2012-02-28 Danny Z. Chen , Haitao Wang

In this article, we determine the amortized computational complexity of the planar dynamic convex hull problem by querying. We present a data structure that maintains a set of n points in the plane under the insertion and deletion of points…

Computational Geometry · Computer Science 2019-03-01 Riko Jacob , Gerth Stølting Brodal

Let $S$ be a set of $n$ points in the plane. We present several different algorithms for finding a pair of points in $S$ such that any disk that contains that pair must contain at least $cn$ points of $S$, for some constant $c>0$. The first…

Computational Geometry · Computer Science 2026-01-29 Prosenjit Bose , Guillermo Esteban , Tyler Tuttle

We present a mathematical and algorithmic scheme for learning the principal geometric elements in an image or 3D object. We build on recent work that convexifies the basic problem of finding a combination of a small number shapes that…

Computer Vision and Pattern Recognition · Computer Science 2016-07-05 Alireza Aghasi , Justin Romberg

We consider the following geometric optimization problem: find a maximum-area rectangle and a maximum-perimeter rectangle contained in a given convex polygon with $n$ vertices. We give exact algorithms that solve these problems in time…

Computational Geometry · Computer Science 2014-10-08 Sergio Cabello , Otfried Cheong , Christian Knauer , Lena Schlipf

CAT(0) metric spaces and hyperbolic spaces play an important role in combinatorial and geometric group theory. In this paper, we present efficient algorithms for distance problems in CAT(0) planar complexes. First of all, we present an…

Computational Geometry · Computer Science 2014-10-09 Daniela Maftuleac

We consider the planar dynamic convex hull problem. In the literature, solutions exist supporting the insertion and deletion of points in poly-logarithmic time and various queries on the convex hull of the current set of points in…

Computational Geometry · Computer Science 2024-03-12 Bruce Brewer , Gerth Stølting Brodal , Haitao Wang

We develop a sketching algorithm to find the point on the convex hull of a dataset, closest to a query point outside it. Studying the convex hull of datasets can provide useful information about their geometric structure and their…

Differential Geometry · Mathematics 2022-03-30 Roozbeh Yousefzadeh