Uniform-machines scheduling: Difference between revisions

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The '''LPT algorithm''' (Longest Processing Time First), also called [[greedy number partitioning]], sorts the jobs by their length, longest first, and then assigns them to the processor with the earliest end time so far. For ''identical'' machines, it asymptotically attains at most 4/3 of the maximum completion time. Iit has good asymptotic convergence properties even for ''uniform'' machines.<ref>{{Cite journal|last=Frenk|first=J. B. G.|last2=Rinnooy Kan|first2=A. H. G.|date=1987-05-01|title=The Asymptotic Optimality of the LPT Rule|url=https://pubsonline.informs.org/doi/abs/10.1287/moor.12.2.241|journal=Mathematics of Operations Research|volume=12|issue=2|pages=241–254|doi=10.1287/moor.12.2.241|issn=0364-765X}}</ref>
 
'''Sahni'''<ref>{{Cite journal|last=Sahni|first=Sartaj K.|date=1976-01-01|title=Algorithms for Scheduling Independent Tasks|url=https://doi.org/10.1145/321921.321934|journal=Journal of the ACM|volume=23|issue=1|pages=116–127|doi=10.1145/321921.321934|issn=0004-5411}}</ref> presented several algorithms for identical machines.
 
'''Horowitz and Sahni<ref name=":0">{{Cite journal|last=Horowitz|first=Ellis|last2=Sahni|first2=Sartaj|date=1976-04-01|title=Exact and Approximate Algorithms for Scheduling Nonidentical Processors|url=https://doi.org/10.1145/321941.321951|journal=Journal of the ACM|volume=23|issue=2|pages=317–327|doi=10.1145/321941.321951|issn=0004-5411}}</ref>''' presented: