# Kunst!

The classical Art Gallery Problem (AGP) asks for the minimum number of guards that achieve visibility coverage of a given polygon. This problem is known to be NP-hard, even for very restricted and discrete special cases. For the general problem (in which both the set of possible guard positions and the point set to be guarded are uncountable), neither constant-factor approximation algorithms nor exact solution methods are known.

Kunst!, is a project at the Institute of Operating Systems and Computer Networks at University of Technology. We develop a primal-dual approach for general art gallery problems in arbitrary polygons with holes, in which guards can be placed anywhere, such that the entire interior of the polygon is guarded. Our method computes a sequence of lower and upper bounds on the optimal number of guards until-in case of convergence and integrality-eventually an optimal solution is reached. Our algorithm is based on a formulation of the problem as a (covering) linear program. It solves the problem using a cutting plane and column generation approach, i.e., by solving the primal and dual separation problems. The picture shows a sample gallery with optimal solution of six guard.

The approach uses the arrangement package of CGAL.

### Links

- For more information and recent publications see the original project page.

### Contact

- Michael Hemmer, TU Braunschweig, Germany