A GRASP for Coloring Sparse Graphs COAP Manuel Laguna and Rafael Marti ------------------------------------------------------ Name and Address of Corresponding Author: Manuel Laguna Graduate School of Business, University of Colorado, Boulder, CO 80309-0419 USA Phone number: (303) 492-6368 Fax number: (303) 492-5962 Email address: manuel.laguna@colorado.edu Web site: http://bus.colorado.edu/faculty/laguna ABSTRACT: We first present a literature review of heuristics and metaheuristics developed for the problem of coloring graphs. We then present a Greedy Randomized Adaptive Search Procedure (GRASP) for coloring sparse graphs. The procedure is tested on graphs of known chromatic number, as well as random graphs with edge probability 0.1 having from 50 to 500 vertices. Empirical results indicate that the proposed GRASP implementation compares favorably to classical heuristics and implementations of simulated annealing and tabu search. GRASP is also found to be competitive with a genetic algorithm that is considered one of the best currently available for graph coloring. Keywords: graph coloring, metaheuristics, GRASP