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We study the Art Gallery Problem under $k$-hop visibility in polyominoes. In this visibility model, two unit squares of a polyomino can see each other if and only if the shortest path between the respective vertices in the dual graph of the…

Computational Geometry · Computer Science 2024-12-25 Omrit Filtser , Erik Krohn , Bengt J. Nilsson , Christian Rieck , Christiane Schmidt

The VC-dimension plays an important role for the algorithmic problem of guarding art galleries efficiently. We prove that inside a simple polygon at most $5$ points can be shattered by $L_1$-visibility polygons and give an example where 5…

Computational Geometry · Computer Science 2017-05-05 Elmar Langetepe , Simone Lehmann

We consider guarding classes of simple polygons using mobile guards (polygon edges and diagonals) under the constraint that no two guards may see each other. In contrast to most other art gallery problems, existence is the primary question:…

Computational Geometry · Computer Science 2012-06-11 Sarah Cannon , Diane L. Souvaine , Andrew Winslow

An orthogonal polygon is called an ortho-unit polygon if its vertices have integer coordinates, and all of its edges have length one. In this paper we prove that any ortho-unit polygon with $n \geq 12$ vertices can be guarded with at most…

Computational Geometry · Computer Science 2025-01-15 J. M. Díaz-Báñez , P. Horn , M. A. Lopez , N. Marín , A. Ramírez-Vigueras , O. Solé-Pi , A. Stevens , J. Urrutia

We are interested in the problem of guarding simple orthogonal polygons with the minimum number of $ r $-guards. The interior point $ p $ belongs an orthogonal polygon $ P $ is visible from $ r $-guard $ g $, if the minimum area rectangle…

Computational Geometry · Computer Science 2017-09-14 Hamid Hoorfar , Alireza Bagheri

The Searchlight Scheduling Problem was first studied in 2D polygons, where the goal is for point guards in fixed positions to rotate searchlights to catch an evasive intruder. Here the problem is extended to 3D polyhedra, with the guards…

Computational Geometry · Computer Science 2015-03-19 Giovanni Viglietta

We present approximation algorithms with O(n^3) processing time for the minimum vertex and edge guard problems in simple polygons. It is improved from previous O(n^4) time algorithms of Ghosh. For simple polygon, there are O(n^3) visibility…

Computational Geometry · Computer Science 2015-03-17 Dae-Sung Jang , Sun-Il Kwon

Art Gallery Localization (AGL) is the problem of placing a set $T$ of broadcast towers in a simple polygon $P$ in order for a point to locate itself in the interior. For any point $p \in P$: for each tower $t \in T \cap V(p)$ (where $V(p)$…

Computational Geometry · Computer Science 2018-11-30 Prosenjit Bose , Jean-Lou De Carufel , Alina Shaikhet , Michiel Smid

There is an old conjecture by Shermer \cite{sher} that in a polygon with $n$ vertices and $h$ holes, $\lfloor \dfrac{n+h}{3} \rfloor$ vertex guards are sufficient to guard the entire polygon. The conjecture is proved for $h=1$ by Shermer…

Computational Geometry · Computer Science 2021-02-23 Sharareh Alipour

In this paper, we study the Contiguous Art Gallery Problem, introduced by Thomas C. Shermer at the 2024 Canadian Conference on Computational Geometry, a variant of the classical art gallery problem from 1973 by Victor Klee. In the…

Computational Geometry · Computer Science 2025-06-30 Magnus Christian Ring Merrild , Casper Moldrup Rysgaard , Jens Kristian Refsgaard Schou , Rolf Svenning

This paper discusses a distance guarding concept on triangulation graphs, which can be associated with distance domination and distance vertex cover. We show how these subjects are interconnected and provide tight bounds for any n-vertex…

Computational Geometry · Computer Science 2013-07-09 Santiago Canales , Gregorio Hernández , Mafalda Martins , Inês Matos

Terrain Guarding Problem(TGP), which is known to be NP-complete, asks to find a smallest set of guard locations on a terrain $T$ such that every point on $T$ is visible by a guard. Here, we study this problem on 1.5D orthogonal terrains…

Computational Geometry · Computer Science 2016-05-19 Yangdi Lyu , Alper Üngör

In the original Art Gallery Problem (AGP), one seeks the minimum number of guards required to cover a polygon $P$. We consider the Chromatic AGP (CAGP), where the guards are colored. As long as $P$ is completely covered, the number of…

Computational Geometry · Computer Science 2014-03-13 Sándor P. Fekete , Stephan Friedrichs , Michael Hemmer

We study the problem of planning paths for a team of robots for visually monitoring an environment. Our work is motivated by surveillance and persistent monitoring applications. We are given a set of target points in a polygonal environment…

Robotics · Computer Science 2016-12-13 Pratap Tokekar , Ashish Kumar Budhiraja , Vijay Kumar

Recently, a natural variant of the Art Gallery problem, known as the \emph{Contiguous Art Gallery problem} was proposed. Given a simple polygon $P$, the goal is to partition its boundary $\partial P$ into the smallest number of contiguous…

Computational Geometry · Computer Science 2026-04-16 Sarita de Berg , Jacobus Conradi , Ivor van der Hoog , Eva Rotenberg

A hidden guard set $ G $ is a set of point guards in polygon $ P $ that all points of the polygon are visible from some guards in $ G $ under the constraint that no two guards may see each other. In this paper, we consider the problem for…

Computational Geometry · Computer Science 2017-08-22 Hamid Hoorfar , Alireza Bagheri

A terrain is an x-monotone polygonal curve, i.e., successive vertices have increasing x-coordinates. Terrain Guarding can be seen as a special case of the famous art gallery problem where one has to place at most $k$ guards on a terrain…

Computational Geometry · Computer Science 2018-07-03 Édouard Bonnet , Panos Giannopoulos

How many chess rooks or queens does it take to guard all the squares of a given polyomino, the union of square tiles from a square grid? This question is a version of the art gallery problem in which the guards can "see" whichever squares…

Computational Complexity · Computer Science 2018-11-21 Hannah Alpert , Érika Roldán

An "edge guard set" of a plane graph $G$ is a subset $\Gamma$ of edges of $G$ such that each face of $G$ is incident to an endpoint of an edge in $\Gamma$. Such a set is said to guard $G$. We improve the known upper bounds on the number of…

Computational Geometry · Computer Science 2018-04-20 Ahmad Biniaz , Prosenjit Bose , Aurélien Ooms , Sander Verdonschot

A $t$-bar visibility representation of a graph assigns each vertex up to $t$ horizontal bars in the plane so that two vertices are adjacent if and only if some bar for one vertex can see some bar for the other via an unobstructed vertical…

Combinatorics · Mathematics 2019-04-19 Yuanrui Feng , Douglas B. West , Yan Yang