Approximating covering problems by randomized search heuristics using multi-objective models

A combination of the 16th International Conference on Genetic Algorithms (ICGA) and the 12th Annual Genetic Programming Conference (GP)The main aim of randomized search heuristics is to produce good approximations of optimal solutions within a small amount of time. In contrast to numerous experimental results, there are only a few theoretical ones on this subject. We consider the approximation ability of randomized search heuristics for the class of covering problems and compare single-objective and multi-objective models for such problems. For the VertexCover problem, we point out situations where the multi-objective model leads to a fast construction of optimal solutions while in the single-objective case even no good approximation can be achieved within expected polynomial time. Examining the more general SetCover problem we show that optimal solutions can be approximated within a factor of log n, where n is the problem dimension, using the multi-objective approach while the approximation quality obtainable by the single-objective approach in expected polynomial time may be arbitrarily bad.Tobias Friedrich, Jun He, Nils Hebbinghaus, Frank Neumann and Carsten Wit