Ommeren, J.C.W. van

facility algorithm approximation demand point problem location cluster approximation algorithms demand point k transportation costs level demand points integer program van ommeren / facility location problem demand point solution constraint facility location problems opening facilities 3- approximation algorithm integer approximation guarantee program transportation integer programming formulation path p approximation algorithm center lemma i ∈ n i ∈ f opening i ∈ vl variable probability paper mathematics guarantee formulation gabor fi y ∗ ommeren i ∈ p k ∈ cc 453–460 computer science cluster center cluster centers proceeding j.-k.c.w shmoy ∗ ∗ programming neighborhood section facility i | f | siam j proof uncapacitated ||vn | constraints polynomial randomized number e l =1 combinatorial · · · level l university zhang l ≥ 2 facility location algorithms il ∈ p aardal meyerson value science munagala