

Shellsort is not O(n log n) but not O(n^2) either - pmiller2
http://www.softpanorama.org/Algorithms/Sorting/shellsort.shtml
I thought I recalled Knuth showing shellsort was better than O(n^2), but worse than O(n log n).  According to this page, shellsort is somewhere around N(log N)^2 and N^(1.25).  The proof is in Knuth, TAOCP.
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pmiller2
I thought I recalled Knuth showing shellsort was better than O(n^2), but worse
than O(n log n). According to this page, shellsort is somewhere around N(log
N)^2 and N^(1.25). The proof is in Knuth, TAOCP.

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pmiller2
Proof of O (n (log n)^2) at: [http://www.inf.fh-
flensburg.de/lang/algorithmen/sortieren/sh...](http://www.inf.fh-
flensburg.de/lang/algorithmen/sortieren/shell/shellen.htm)

