1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Function template reverse_string_sort</title> 5<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Boost.Sort"> 8<link rel="up" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html" title="Header <boost/sort/spreadsort/string_sort.hpp>"> 9<link rel="prev" href="string_s_idm45878543498160.html" title="Function template string_sort"> 10<link rel="next" href="reverse__idm45878543439168.html" title="Function template reverse_string_sort"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> 15<td align="center"><a 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name="boost.sort.spreadsort.reverse__idm45878543470704"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Function template reverse_string_sort</span></h2> 29<p>boost::sort::spreadsort::reverse_string_sort — Reverse String sort algorithm using random access iterators. </p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html" title="Header <boost/sort/spreadsort/string_sort.hpp>">boost/sort/spreadsort/string_sort.hpp</a>> 33 34</span> 35<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> RandomAccessIter<span class="special">,</span> <span class="keyword">typename</span> Get_char<span class="special">,</span> <span class="keyword">typename</span> Get_length<span class="special">,</span> 36 <span class="keyword">typename</span> Compare<span class="special">></span> 37 <span class="keyword">void</span> <span class="identifier">reverse_string_sort</span><span class="special">(</span><span class="identifier">RandomAccessIter</span> first<span class="special">,</span> <span class="identifier">RandomAccessIter</span> last<span class="special">,</span> 38 <span class="identifier">Get_char</span> get_character<span class="special">,</span> <span class="identifier">Get_length</span> length<span class="special">,</span> 39 <span class="identifier">Compare</span> comp<span class="special">)</span><span class="special">;</span></pre></div> 40<div class="refsect1"> 41<a name="idm45477844113536"></a><h2>Description</h2> 42<p>(All variants fall back to <code class="computeroutput">boost::sort::pdqsort</code> if the data size is too small, < <code class="computeroutput">detail::min_sort_size</code>).</p> 43<p><code class="computeroutput">string_sort</code> is a fast templated in-place hybrid radix/comparison algorithm, which in testing tends to be roughly 50% to 2X faster than <code class="computeroutput">std::sort</code> for large tests (>=100kB).<br> 44</p> 45<p><b> </b>Worst-case performance is <span class="emphasis"><em> O(N * (lg(range)/s + s)) </em></span>, so <code class="computeroutput">string_sort</code> is asymptotically faster than pure comparison-based algorithms. <br> 46<br> 47Some performance plots of runtime vs. n and log(range) are provided:<br> 48<a href="../../../../../doc/graph/windows_string_sort.htm" target="_top">windows_string_sort</a><br> 49<a href="../../../../../doc/graph/osx_string_sort.htm" target="_top">osx_string_sort</a></p> 50<p> 51 52 53 54 55 56 57 58</p> 59<div class="warning"><table border="0" summary="Warning"> 60<tr> 61<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../doc/src/images/warning.png"></td> 62<th align="left">Warning</th> 63</tr> 64<tr><td align="left" valign="top"><p>Throwing an exception may cause data loss. This will also throw if a small vector resize throws, in which case there will be no data loss. </p></td></tr> 65</table></div> 66<p> 67</p> 68<div class="warning"><table border="0" summary="Warning"> 69<tr> 70<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../doc/src/images/warning.png"></td> 71<th align="left">Warning</th> 72</tr> 73<tr><td align="left" valign="top"><p>Invalid arguments cause undefined behaviour. </p></td></tr> 74</table></div> 75<p> 76</p> 77<div class="note"><table border="0" summary="Note"> 78<tr> 79<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td> 80<th align="left">Note</th> 81</tr> 82<tr><td align="left" valign="top"><p><code class="computeroutput">spreadsort</code> function provides a wrapper that calls the fastest sorting algorithm available for a data type, enabling faster generic-programming.</p></td></tr> 83</table></div> 84<p> 85</p> 86<p>The lesser of <span class="emphasis"><em> O(N*log(N)) </em></span> comparisons and <span class="emphasis"><em> O(N*log(K/S + S)) </em></span>operations worst-case, where: </p> 87<p> 88 89</p> 90<p>* N is <code class="computeroutput">last</code> - <code class="computeroutput">first</code>, </p> 91<p> 92 93</p> 94<p>* K is the log of the range in bits (32 for 32-bit integers using their full range), </p> 95<p> 96 97</p> 98<p>* S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size). </p> 99<p> 100 101</p> 102<div class="variablelist"><table border="0" class="variablelist compact"> 103<colgroup> 104<col align="left" valign="top"> 105<col> 106</colgroup> 107<tbody> 108<tr> 109<td><p><span class="term">Parameters:</span></p></td> 110<td><div class="variablelist"><table border="0" class="variablelist compact"> 111<colgroup> 112<col align="left" valign="top"> 113<col> 114</colgroup> 115<tbody> 116<tr> 117<td><p><span class="term"><code class="computeroutput">comp</code></span></p></td> 118<td><p>A binary functor that returns whether the first element passed to it should go before the second in order.</p></td> 119</tr> 120<tr> 121<td><p><span class="term"><code class="computeroutput">first</code></span></p></td> 122<td><p>Iterator pointer to first element. </p></td> 123</tr> 124<tr> 125<td><p><span class="term"><code class="computeroutput">get_character</code></span></p></td> 126<td><p>Bracket functor equivalent to <code class="computeroutput">operator</code>[], taking a number corresponding to the character offset. </p></td> 127</tr> 128<tr> 129<td><p><span class="term"><code class="computeroutput">last</code></span></p></td> 130<td><p>Iterator pointing to one beyond the end of data. </p></td> 131</tr> 132<tr> 133<td><p><span class="term"><code class="computeroutput">length</code></span></p></td> 134<td><p>Functor to get the length of the string in characters. </p></td> 135</tr> 136</tbody> 137</table></div></td> 138</tr> 139<tr> 140<td><p><span class="term">Requires:</span></p></td> 141<td><p>[<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) is a valid range. </p></td> 142</tr> 143<tr> 144<td><p><span class="term">Requires:</span></p></td> 145<td><p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> is mutable. </p></td> 146</tr> 147<tr> 148<td><p><span class="term">Requires:</span></p></td> 149<td><p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> is <a href="http://en.cppreference.com/w/cpp/concept/LessThanComparable" target="_top">LessThanComparable</a> </p></td> 150</tr> 151<tr> 152<td><p><span class="term">Postconditions:</span></p></td> 153<td><p>The elements in the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) are sorted in ascending order.</p></td> 154</tr> 155<tr> 156<td><p><span class="term">Returns:</span></p></td> 157<td><p><code class="computeroutput">void</code>.</p></td> 158</tr> 159<tr> 160<td><p><span class="term">Throws:</span></p></td> 161<td>std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves), the right shift, subtraction of right-shifted elements, functors, or any operations on iterators throw.</td> 162</tr> 163</tbody> 164</table></div> 165</div> 166</div> 167<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 168<td align="left"></td> 169<td align="right"><div class="copyright-footer">Copyright © 2014-2017 Steven 170 Ross, Francisco Tapia, Orson Peters<p> 171 Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost 172 Software License, Version 1.0</a>. 173 </p> 174</div></td> 175</tr></table> 176<hr> 177<div class="spirit-nav"> 178<a accesskey="p" href="string_s_idm45878543498160.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="reverse__idm45878543439168.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 179</div> 180</body> 181</html> 182
