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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="sort.sort_hpp.integer_sort"></a><a class="link" href="integer_sort.html" title="Integer Sort">Integer Sort</a> |
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| <p> |
| <code class="literal"><code class="computeroutput"><a class="link" href="../../boost/sort/spreadsort/integer_sort_idp41299456.html" title="Function template integer_sort">integer_sort</a></code></code> |
| is a fast templated in-place hybrid radix/comparison algorithm, which in |
| testing tends to be roughly 50% to 2X faster than <a href="http://en.cppreference.com/w/cpp/algorithm/sort" target="_top">std::sort</a> |
| for large tests (>=100kB). Worst-case performance is <span class="emphasis"><em>𝑶(N * (log2(range)/s |
| + s))</em></span>, so <code class="literal"><code class="computeroutput"><a class="link" href="../../boost/sort/spreadsort/integer_sort_idp41299456.html" title="Function template integer_sort">integer_sort</a></code></code> |
| is asymptotically faster than pure comparison-based algorithms. <span class="emphasis"><em>s</em></span> |
| is <span class="emphasis"><em>max_splits</em></span>, which defaults to 11, so its worst-case |
| with default settings for 32-bit integers is <span class="emphasis"><em>𝑶(N * ((32/11)</em></span> |
| slow radix-based iterations + 11 fast comparison-based iterations). |
| </p> |
| <p> |
| Some performance plots of runtime vs. n and log2(range) are provided below: |
| </p> |
| <p> |
| <a href="../../../../doc/graph/windows_integer_sort.htm" target="_top">Windows Integer Sort</a> |
| </p> |
| <p> |
| <a href="../../../../doc/graph/osx_integer_sort.htm" target="_top">OSX integer Sort</a> |
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| <div class="section"> |
| <div class="titlepage"><div><div><h4 class="title"> |
| <a name="sort.sort_hpp.integer_sort.integersort_examples"></a><a class="link" href="integer_sort.html#sort.sort_hpp.integer_sort.integersort_examples" title="Integer Sort Examples">Integer |
| Sort Examples</a> |
| </h4></div></div></div> |
| <p> |
| See <a href="../../../../example/rightshiftsample.cpp" target="_top">rightshiftsample.cpp</a> |
| for a working example of using rightshift, using a user-defined functor: |
| </p> |
| <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">rightshift</span> <span class="special">{</span> |
| <span class="keyword">inline</span> <span class="keyword">int</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">DATA_TYPE</span> <span class="identifier">x</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="identifier">offset</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">x</span> <span class="special">>></span> <span class="identifier">offset</span><span class="special">;</span> <span class="special">}</span> |
| <span class="special">};</span> |
| </pre> |
| <p> |
| Other examples: |
| </p> |
| <p> |
| <a href="../../../../example/keyplusdatasample.cpp" target="_top">Sort structs using an |
| integer key.</a> |
| </p> |
| <p> |
| <a href="../../../../example/reverseintsample.cpp" target="_top">Sort integers in reverse |
| order.</a> |
| </p> |
| <p> |
| <a href="../../../../example/mostlysorted.cpp" target="_top">Simple sorting of integers; |
| this case is a performance test for integers that are already mostly sorted.</a> |
| </p> |
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| <td align="right"><div class="copyright-footer">Copyright © 2014 Steven Ross<p> |
| Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost |
| Software License, Version 1.0</a>. |
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