Improved Approximation Algorithms for Uncapitated Facility Location
نویسنده
چکیده
We consider the uncapacitated facility location problem. In this problem, there is a set of locations at which facilities can be built; a xed cost f i is incurred if a facility is opened at location i. Furthermore, there is a set of demand locations to be serviced by the opened facilities; if the demand location j is assigned to a facility at location i, then there is an associated service cost of c ij. We assume that the assignment costs c ij are symmetric and satisfy the triangle inequality. For this problem we obtain a (1+2=e)-approximation algorithm, where 1+2=e 1:736, a signiicant improvement on the previously known approximation guarantees. The algorithm works by rounding an optimal fractional solution to a linear programming relaxation. Our techniques use properties of optimal solutions to the linear program, randomized rounding, as well as a generalization of the decomposition techniques of Shmoys, Tardos & Aardal.
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تاریخ انتشار 1998