Transforming rectangles into squares An introduction to the squarability problem

نویسندگان

  • Jonathan Klawitter
  • Torsten Ueckerdt
چکیده

In this bachelor thesis we introduce the Squarability problem: When can a set of axisaligned rectangles be transformed into squares without changing combinatorial properties? This means, that we do not allow to change whether, how and in which order the rectangles respectively squares intersect. We use a sweep line algorithm to compute the combinatorial information from geometrically given rectangles. We give a full characterisation of triangle-free rectangle arrangements via enhanced intersection graphs. We define a mixed integer linear program to solve any instance of the Squarability problem. We give some exemplary instances, which indicate that the problem is in general not that easy to solve. However, we show that some classes of rectangle arrangements can always be transformed into squares in the desired way.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Squarability of rectangle arrangements

We study when an arrangement of axis-aligned rectangles can be transformed into an arrangement of axisaligned squares in R while preserving its structure. We found a counterexample to the conjecture of J. Klawitter, M. Nöllenburg and T. Ueckerdt whether all arrangements without crossing and side-piercing can be squared. Our counterexample also works in a more general case when we only need to p...

متن کامل

A Fast Algorithm for Covering Rectangular Orthogonal Polygons with a Minimum Number of r-Stars

Introduction This paper presents an algorithm for covering orthogonal polygons with minimal number of guards. This idea examines the minimum number of guards for orthogonal simple polygons (without holes) for all scenarios and can also find a rectangular area for each guards. We consider the problem of covering orthogonal polygons with a minimum number of r-stars. In each orthogonal polygon P,...

متن کامل

Combinatorial Properties of Triangle-Free Rectangle Arrangements and the Squarability Problem

We consider arrangements of axis-aligned rectangles in the plane. A geometric arrangement specifies the coordinates of all rectangles, while a combinatorial arrangement specifies only the respective intersection type in which each pair of rectangles intersects. First, we investigate combinatorial contact arrangements, i.e., arrangements of interior-disjoint rectangles, with a triangle-free inte...

متن کامل

Packing Rectangles into 2OPT Bins Using Rotations

We consider the problem of packing rectangles into bins that are unit squares, where the goal is to minimize the number of bins used. All rectangles can be rotated by 90 degrees and have to be packed nonoverlapping and orthogonal, i.e., axis-parallel. We present an algorithm for this problem with an absolute worst-case ratio of 2, which is optimal provided P 6= NP.

متن کامل

Optimal rectangle packing

We consider the NP-complete problem of finding an enclosing rectangle of minimum area that will contain a given a set of rectangles. We present two different constraintsatisfaction formulations of this problem. The first searches a space of absolute placements of rectangles in the enclosing rectangle, while the other searches a space of relative placements between pairs of rectangles. Both appr...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2014