﻿<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/"><channel><title>BlogJava-猪-随笔分类-算法</title><link>http://www.blogjava.net/liuspring/category/35445.html</link><description>java .net</description><language>zh-cn</language><lastBuildDate>Thu, 23 Oct 2008 09:44:17 GMT</lastBuildDate><pubDate>Thu, 23 Oct 2008 09:44:17 GMT</pubDate><ttl>60</ttl><item><title>随机快速排序算法</title><link>http://www.blogjava.net/liuspring/archive/2008/10/23/236213.html</link><dc:creator>猪</dc:creator><author>猪</author><pubDate>Thu, 23 Oct 2008 09:24:00 GMT</pubDate><guid>http://www.blogjava.net/liuspring/archive/2008/10/23/236213.html</guid><wfw:comment>http://www.blogjava.net/liuspring/comments/236213.html</wfw:comment><comments>http://www.blogjava.net/liuspring/archive/2008/10/23/236213.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/liuspring/comments/commentRss/236213.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/liuspring/services/trackbacks/236213.html</trackback:ping><description><![CDATA[随机快速排序算法：
<br />
还没怎么整明白，有点晕<br />
<u>Java语言</u>:
<div style="font-family: &quot;Courier New&quot;,&quot;Lucida Console&quot;,&quot;monospace&quot;; background-color: rgb(249, 247, 237);" class="source">import java.util.*;<br />
<span style="color: rgb(0, 0, 128); font-weight: bold;">public</span> <span style="color: rgb(0, 0, 128); font-weight: bold;">class</span> Test {<br />
<br />
<br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span>[] x = {<span style="color: rgb(0, 0, 255);">3</span>,<span style="color: rgb(0, 0, 255);">7</span>,<span style="color: rgb(0, 0, 255);">5</span>,<span style="color: rgb(0, 0, 255);">6</span>,<span style="color: rgb(0, 0, 255);">4</span>,<span style="color: rgb(0, 0, 255);">9</span>,<span style="color: rgb(0, 0, 255);">8</span>,<span style="color: rgb(0, 0, 255);">1</span>};<br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> comps = <span style="color: rgb(0, 0, 255);">0</span>;<br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">void</span> quicksort(<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> l, <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> u)<br />
&nbsp;&nbsp;&nbsp; { <br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> i, m;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">if</span> (l &gt;= u) <span style="color: rgb(0, 0, 128); font-weight: bold;">return</span>;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; swap(l, getRandom(l, u));<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; m = l;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; comps += u - <span style="color: rgb(0, 0, 255);">1</span>;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">for</span> (i = l+<span style="color: rgb(0, 0, 255);">1</span>; i &lt;= u; i++){<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 136, 0); font-style: italic;">//comps++;</span><br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">if</span> (x[i] &lt; x[l])<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; swap(++m, i);<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; swap(l, m);<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; quicksort(l, m-<span style="color: rgb(0, 0, 255);">1</span>);<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; quicksort(m+<span style="color: rgb(0, 0, 255);">1</span>, u);<br />
&nbsp;&nbsp;&nbsp; }<br />
&nbsp;&nbsp;&nbsp; <br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">void</span> swap(<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> a,<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> b){<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> temp = x[a];<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; x[a] = x[b];<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; x[b] = temp;<br />
&nbsp;&nbsp;&nbsp; }<br />
&nbsp;&nbsp;&nbsp; <br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> getRandom(<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> min,<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span> max){&nbsp; <br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">return</span> (<span style="color: rgb(0, 0, 128); font-weight: bold;">int</span>)(Math.<span style="color: rgb(255, 0, 0);">random</span>()*(max-min+<span style="color: rgb(0, 0, 255);">1</span>)) + min;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 136, 0); font-style: italic;">//Math.round(Math.random()*(Max-Min)+Min);</span><br />
&nbsp;&nbsp;&nbsp; }<br />
&nbsp;&nbsp;&nbsp; <br />
&nbsp;&nbsp;&nbsp; <span style="color: rgb(0, 0, 128); font-weight: bold;">public</span> <span style="color: rgb(0, 0, 128); font-weight: bold;">static</span> <span style="color: rgb(0, 0, 128); font-weight: bold;">void</span> main(String[] args) {<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Test t = <span style="color: rgb(0, 0, 128); font-weight: bold;">new</span> Test();<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; System.<span style="color: rgb(255, 0, 0);">out</span>.<span style="color: rgb(255, 0, 0);">println</span>(Arrays.<span style="color: rgb(255, 0, 0);">toString</span>(t.<span style="color: rgb(255, 0, 0);">x</span>));<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.<span style="color: rgb(255, 0, 0);">quicksort</span>(<span style="color: rgb(0, 0, 255);">0</span>,t.<span style="color: rgb(255, 0, 0);">x</span>.<span style="color: rgb(255, 0, 0);">length</span> - <span style="color: rgb(0, 0, 255);">1</span>);<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; System.<span style="color: rgb(255, 0, 0);">out</span>.<span style="color: rgb(255, 0, 0);">println</span>(t.<span style="color: rgb(255, 0, 0);">comps</span>);<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; System.<span style="color: rgb(255, 0, 0);">out</span>.<span style="color: rgb(255, 0, 0);">println</span>(Arrays.<span style="color: rgb(255, 0, 0);">toString</span>(t.<span style="color: rgb(255, 0, 0);">x</span>));<br />
&nbsp;&nbsp;&nbsp; }<br />
&nbsp;&nbsp;&nbsp; <br />
<br />
}<br />
</div>
<br />
<br />
<img src ="http://www.blogjava.net/liuspring/aggbug/236213.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/liuspring/" target="_blank">猪</a> 2008-10-23 17:24 <a href="http://www.blogjava.net/liuspring/archive/2008/10/23/236213.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>