Optimal space coverage with white convex polygons
نویسندگان
چکیده
Assume that we are given a set of points some of which are black and the rest are white. The goal is to find a set of convex polygons with maximum total area that cover all white points and exclude all black points. We study the problem on three different settings (based on overlapping between different convex polygons): (1) In case convex polygons are permitted to have common area, we present a polynomial algorithm. (2) In case convex polygons are not allowed to have common area but are allowed to have common vertices, we prove the NP-hardness of the problem and propose an algorithm whose output is at least ( O PT log(2n/O PT )+2log(n) )1/4 . (3) Finally, in case convex polygons are not allowed to have common area or common vertices, also we prove the NP-hardness of the problem and propose an algorithm whose output is at least 3 √ 3 4.π ( O PT log(2n/O PT )+2log(n) )1/4 .
منابع مشابه
Automatically-generated Convex Region Decomposition for Real-time Spatial Agent Navigation in Virtual Worlds
This paper presents a new method for decomposing environments of complex geometry into a navigation mesh represented by bounding geometry and a connectivity graph for real-time agent usage in virtual worlds. This is accomplished by the generation of a well-defined and high-coverage set of convex navigable regions and the connected gateways between them. The focus of this paper is a new automate...
متن کاملOptimal Algorithms for Stabbing Polygons by Monotone Chains
In this paper we present optimal algorithms to compute monotone stabbers for convex polygons. More precisely, given a set of m convex polygons with n vertices in total we want to stab the polygons with an x-monotone polygonal chain such that each polygon is entered at its leftmost point and departed at its rightmost point. Since such a stabber does not exist in general, we study two related pro...
متن کاملSmall deformations of polygons and polyhedra
We describe the first-order variations of the angles of Euclidean, spherical or hyperbolic polygons under infinitesimal deformations such that the lengths of the edges do not change. Using this description, we introduce a quadratic invariant on the space of first-order deformations of a polygon. For convex polygons, this quadratic invariant has a positivity property, leading to a new proof of t...
متن کاملOptimal Shortest Path and Minimum-Link Path Queries Between Two Convex Polygons Inside a Simple Polygonal Obstacle
We present e cient algorithms for shortest path and minimum link path queries between two convex polygons inside a simple polygon P which acts as an obstacle to be avoided Let n be the number of vertices of P and h the total number of vertices of the query polygons We show that shortest path queries can be performed optimally in time O logh logn plus O k time for reporting the k edges of the pa...
متن کاملOptimal Shortest Path and Minimum-link Path Queries between Two Convex Polygons in the Presence of Obstacles Optimal Shortest Path and Minimum-link Path Queries between Two Convex Polygons in the Presence of Obstacles
We present eecient algorithms for shortest-path and minimum-link-path queries between two convex polygons inside a simple polygon P, which acts as an obstacle to be avoided. Let n be the number of vertices of P, and h the total number of vertices of the query polygons. We show that shortest-path queries can be performed optimally in time O(log h + logn) (plus O(k) time for reporting the k edges...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- J. Comb. Optim.
دوره 32 شماره
صفحات -
تاریخ انتشار 2016