An Optimal Bifactor Approximation Algorithm for the Metric Uncapacitated Facility Location Problem

We obtain a 1.5-approximation algorithm for the metric uncapacitated facility location (UFL) problem, which improves on the previously best known 1.52-approximation algorithm by Mahdian, Ye, and Zhang. Note that the approximability lower bound by Guha and Khuller is 1.463 . . . . An algorithm is a (?f ,?c)-approximation algorithm if the solution...