A framework for adaptive sorting

  • Ola Petersson
  • Alistair Moffat
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 621)


A sorting algorithm is adaptive if it sorts sequences that are close to sorted faster than it sorts random sequences, where the distance is determined by some measure of presortedness. Over the years several measures of presortedness have been proposed in the literature, but it has been far from clear how they relate to each other. We show that there exists a natural partial order on the set of measures, which makes it possible to say that some measures are superior to others. We insert all known measures of presortedness into the partial order, and thereby provide a powerful tool for evaluating both measures and adaptive sorting algorithms. We further present a new measure and show that it is a maximal known element in the partial order, and thus that any sorting algorithm that optimally adapts to the new measure also optimally adapts to all other known measures of presortedness.


Partial Order Sorting Algorithm Insertion Position Natural Partial Order Sort Sequence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1992

Authors and Affiliations

  • Ola Petersson
    • 1
  • Alistair Moffat
    • 2
  1. 1.Dept. Comp. Sci.Lund Univ.LundSweden
  2. 2.Dept. Comp. Sci.Univ. MelbourneParkvilleAustralia

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