We consider randomized algorithms for the preemptive job shop problem, or equivalently, the case in which all operations have unit length. We give an improved approximation ratio of for an arbitrary number m of machines, the first
approximation for all constant numbers of machines, and an
approximation for the case of two machines where
< 1.45. The last result is via an approximation algorithm for a string matching problem which is of independent interest.
By: Nikhil Bansal, Tracy Kimbrel, Maxim Sviridenko
Published in: RC23273 in 2004
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