CABRO: Winner Determination Algorithm for Single-unit Combinatorial Auctions

In this paper we present CABRO, an algorithm for solving the winner determination problem related to single-unit combinatorial auctions. The algorithm is divided in three main phases. The first phase is a pre-processing step with some reduction techniques. The second phase calculates an tipper and a lower bound based on a linear programming relaxation in order to delete more bids. Finally, the third phase is a branch and bound depth first search where the linear programming relaxation is used as upper bounding and sorting strategy. Experiments against specific solvers like CASS mid general purpose MIP solvers its GLPK and CPLEX show that CABRO is in average the fastest free solver (CPLEX not included), and in some instances drastically faster than any other.