1997	 Increasing the Efficiency of Quicksort	 A method is presented for the analysis of various generalizations of quicksort. The average asymptotic number of comparisons needed is shown to be an log n . A formula is derived expressing a in terms of the probability distribution of the bound of a partition. This formula assumes a particularly simple form for a generalization already considered by Hoare namely choice of the bound as median of a random sample. The main contribution of this paper is another generalization of quicksort which uses a bounding interval instead of a single element as bound. This generalization turns out to be easy to implement in a computer program. A numerical approximation shows that a . for this version of quicksort compared with . for the original. This implies a decrease in number of comparisons of percent actual tests showed about percent saving in computing time. sorting quicksort information content entropy distribution of median
