منابع مشابه
Shellsort with three increments
A perturbation technique can be used to simplify and sharpen A. C. Yao's theorems about the behavior of shellsort with increments (h; g; 1). In particular, when h = (n 7=15) and g = (h 1=5), the average running time is O(n 23=15). The proof involves interesting properties of the inversions in random permutations that have been h-sorted and g-sorted. Shellsort, also known as the \diminishing inc...
متن کاملBest Increments for the Average Case of Shellsort
This paper presents the results of using sequential analysis to find increment sequences that minimize the average running time of Shellsort, for array sizes up to several thousand elements. The obtained sequences outperform by about 3% the best ones known so far, and there is a plausible evidence that they are the optimal ones.
متن کاملLower Bounds for Shellsort
We show lower bounds on the worst-case complexity of Shellsort. In particular, we give a fairly simple proof of an (n lg 2 n=(lg lg n) 2) lower bound for the size of Shellsort sorting networks, for arbitrary increment sequences. We also show an identical lower bound for the running time of Shellsort algorithms, again for arbitrary increment sequences. Our lower bounds establish an almost tight ...
متن کاملAn Improved Shellsort Algorithm
Shellsort algorithm is a refinement of the straight insertion soIt. Each pass of this method sorts all items which are h-position apart by straight insertion sort, and the place of the item to be inserted in is determined by comparing items which are already ordered from right to left. In this paper, straight insertion of h-step length is improved to binary insertion of h-step length. So the nu...
متن کاملAverage-Case Complexity of Shellsort
We prove a general lower bound on the average-case complexity of Shellsort: the average number of data-movements (and comparisons) made by a p-pass Shellsort for any incremental sequence is Ω(pn 1 p ) for all p ≤ logn. Using similar arguments, we analyze the average-case complexity of several other sorting algorithms.
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ژورنال
عنوان ژورنال: Random Structures and Algorithms
سال: 1997
ISSN: 1042-9832,1098-2418
DOI: 10.1002/(sici)1098-2418(199701/03)10:1/2<125::aid-rsa6>3.3.co;2-q