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We study the problem of unsupervised discovery and segmentation of object parts, which, as an intermediate local representation, are capable of finding intrinsic object structure and providing more explainable recognition results. Recent…

Computer Vision and Pattern Recognition · Computer Science 2021-05-27 Shilong Liu , Lei Zhang , Xiao Yang , Hang Su , Jun Zhu

We present a new algorithm for computing the straight skeleton of a polygon. For a polygon with $n$ vertices, among which $r$ are reflex vertices, we give a deterministic algorithm that reduces the straight skeleton computation to a…

Computational Geometry · Computer Science 2014-07-15 Siu-Wing Cheng , Liam Mencel , Antoine Vigneron

Guarding a polygon with few guards is an old and well-studied problem in computational geometry. Here we consider the following variant: We assume that the polygon is orthogonal and thin in some sense, and we consider a point $p$ to guard a…

Computational Geometry · Computer Science 2016-04-26 Therese Biedl , Saeed Mehrabi

We consider compact representations of collections of similar strings that support random access queries. The collection of strings is given by a rooted tree where edges are labeled by an edit operation (inserting, deleting, or replacing a…

Data Structures and Algorithms · Computer Science 2021-02-12 Philip Bille , Inge Li Gørtz

We study the problem of partitioning integer sequences in the one-pass data streaming model. Given is an input stream of integers $X \in \{0, 1, \dots, m \}^n$ of length $n$ with maximum element $m$, and a parameter $p$. The goal is to…

Data Structures and Algorithms · Computer Science 2014-07-08 Christian Konrad , László Kozma

In the two-dimensional orthogonal colored range counting problem, we preprocess a set, $P$, of $n$ colored points on the plane, such that given an orthogonal query rectangle, the number of distinct colors of the points contained in this…

Computational Geometry · Computer Science 2021-07-07 Younan Gao , Meng He

We study approximation algorithms for the following geometric version of the maximum coverage problem: Let $\mathcal{P}$ be a set of $n$ weighted points in the plane. Let $D$ represent a planar object, such as a rectangle, or a disk. We…

Computational Geometry · Computer Science 2017-12-08 Kai Jin , Jian Li , Haitao Wang , Bowei Zhang , Ningye Zhang

Given a set $P$ of $n$ points in the plane, we consider the problem of computing the number of points of $P$ in a query unit disk (i.e., all query disks have the same radius). We show that the main techniques for simplex range searching in…

Computational Geometry · Computer Science 2022-04-20 Haitao Wang

We study the minimum membership geometric set cover, i.e., MMGSC problem [SoCG, 2023] in the continuous setting. In this problem, the input consists of a set $P$ of $n$ points in $\mathbb{R}^{2}$, and a geometric object $t$, the goal is to…

Computational Geometry · Computer Science 2025-06-03 Sathish Govindarajan , Mayuresh Patle , Siddhartha Sarkar

Two algorithms for computing $P(n,m)$, the number of integer partitions of $n$ into exactly $m$ parts, are described, and using a combination of these two algorithms, the resulting algorithm is $O(n^{3/2})$. The second algorithm uses a list…

Number Theory · Mathematics 2022-06-07 M. J. Kronenburg

We consider the problem of finding k centers for n weighted points on a real line. This (weighted) k-center problem was solved in O(n log n) time previously by using Cole's parametric search and other complicated approaches. In this paper,…

Computational Geometry · Computer Science 2014-03-07 Danny Z. Chen , Jian Li , Haitao Wang

We consider the problem of routing a data packet through the visibility graph of a polygonal domain $P$ with $n$ vertices and $h$ holes. We may preprocess $P$ to obtain a label and a routing table for each vertex of $P$. Then, we must be…

This paper introduces a novel $k$-cell decomposition method for pursuit-evasion problems in polygonal environments, where a searcher is equipped with a $k$-modem: a device capable of seeing through up to $k$ walls. The proposed…

Computational Geometry · Computer Science 2025-11-06 Yeganeh Bahoo , Sajad Saeedi , Roni Sherman

Can Grover's algorithm speed up search of a physical region - for example a 2-D grid of size sqrt(n) by sqrt(n)? The problem is that sqrt(n) time seems to be needed for each query, just to move amplitude across the grid. Here we show that…

Quantum Physics · Physics 2007-05-23 Scott Aaronson , Andris Ambainis

In the orthogonal range reporting problem we must pre-process a set $P$ of multi-dimensional points, so that for any axis-parallel query rectangle $q$ all points from $q\cap P$ can be reported efficiently. In this paper we study the query…

Data Structures and Algorithms · Computer Science 2022-11-08 Yakov Nekrich , Saladi Rahul

We describe a polynomial time algorithm that takes as input a polygon with axis-parallel sides but irrational vertex coordinates, and outputs a set of as few rectangles as possible into which it can be dissected by axis-parallel cuts and…

Computational Geometry · Computer Science 2025-01-08 David Eppstein

Given a set $P$ of $n$ points in the plane, its separability is the minimum number of lines needed to separate all its pairs of points from each other. We show that the minimum number of lines needed to separate $n$ points, picked randomly…

Computational Geometry · Computer Science 2017-06-08 Sariel Har-Peled , Mitchell Jones

Neighborhood graphs are gaining popularity as a concise data representation in machine learning. However, naive graph construction by pairwise distance calculation takes $O(n^2)$ runtime for $n$ data points and this is prohibitively slow…

Data Structures and Algorithms · Computer Science 2009-04-22 Takeaki Uno , Masashi Sugiyama , Koji Tsuda

Counting objects in images is a pattern recognition problem that focuses on identifying an element to determine its incidence and is approached in the literature as Visual Object Counting (VOC). In this work, we propose a methodology to…

Computer Vision and Pattern Recognition · Computer Science 2023-09-04 João V. C. Mazzochin , Gustavo Tiecker , Erick O. Rodrigues

Given an $n$-vertex planar embedded digraph $G$ with non-negative edge weights and a face $f$ of $G$, Klein presented a data structure with $O(n\log n)$ space and preprocessing time which can answer any query $(u,v)$ for the shortest path…

Data Structures and Algorithms · Computer Science 2023-07-31 Debarati Das , Evangelos Kipouridis , Maximilian Probst Gutenberg , Christian Wulff-Nilsen