vim-castle/.vim/vimwiki/vimwiki_html/Shell Sort.html

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<link rel="Stylesheet" type="text/css" href="style.css">
<title>Shell Sort</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<h2 id="toc_0.1">Shell Sort</h2>
<dl>
<dt>Stats</dt>
<dd>Worst Case Performance: O(n<sup><small>2</small></sup>)</dd>
<dd>Best Case Performance: O(n log n)</dd>
<dd>Created in 1959 by Donald <strong>Shell</strong></dd>
</dl>
<h3 id="toc_0.1.1">Psuedocode</h3>
<pre>
// This is the array to be sorted
gaps = [701, 301, 132, 57, 23, 10, 4, 1]
// Start with the largest gap and work down to a gap of 1
foreach(gap in gaps) {
// Do a gapped insertion sort for this gap size.
// The first gap elements a[0..gap-1] are already in gapped order
// keep adding one more element until the entire array is gap sorted
for(i = gap; i &lt; n; i += 1) {
// Add gaps[i] to the elements that have been gap sorted
// save gaps[i] in temp and make a hole at position i
temp = gaps[i]
// Shift earlier gap-sorted elements up until the correct location for gaps[i] is found
for(j = i; j &gt;= gap and gaps[j - gap] &gt; temp; j -= gap) {
gaps[j] = gaps[j - gap]
}
// Put temp (the original gaps[i]) in its correct location
gaps[j] = temp
}
}
</pre>
<h3 id="toc_0.1.2">Additional Info</h3>
<p>
Wikipedia Article: [<a href="http://en.wikipedia.org/wiki/Shell_sort]">http://en.wikipedia.org/wiki/Shell_sort]</a>
</p>
</body>
</html>