On the linear relaxation of the p-median problem

Abstract

We study a well-known linear programming relaxation of the p-median problem. We give a characterization of the directed graphs for which this system of inequalities defines an integral polytope. As a consequence, we obtain that the p-median problem is polynomial in that class of graphs. We also give an algorithm to recognize these graphs. © 2011 Elsevier B.V. All rights reserved.