﻿<?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>C++博客-I believe-随笔分类-陷阱题</title><link>http://www.cppblog.com/luyulaile/category/10548.html</link><description>I  can</description><language>zh-cn</language><lastBuildDate>Sun, 19 Jul 2009 12:49:12 GMT</lastBuildDate><pubDate>Sun, 19 Jul 2009 12:49:12 GMT</pubDate><ttl>60</ttl><item><title>joj 2236 Balance and Poise 好题</title><link>http://www.cppblog.com/luyulaile/archive/2009/07/19/90523.html</link><dc:creator>luis</dc:creator><author>luis</author><pubDate>Sun, 19 Jul 2009 07:46:00 GMT</pubDate><guid>http://www.cppblog.com/luyulaile/archive/2009/07/19/90523.html</guid><wfw:comment>http://www.cppblog.com/luyulaile/comments/90523.html</wfw:comment><comments>http://www.cppblog.com/luyulaile/archive/2009/07/19/90523.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.cppblog.com/luyulaile/comments/commentRss/90523.html</wfw:commentRss><trackback:ping>http://www.cppblog.com/luyulaile/services/trackbacks/90523.html</trackback:ping><description><![CDATA[<div class=prob_text>
<p>工匠大师Hill打造出一个精致的天平, 对他的徒弟Oren说：&#8220;你帮我做一些砝码配套，为了方便携带，砝码数目要尽量少&#8221;。 </p>
Oren：&#8220;好。我将按照2进制的规则打造，也就是1，2，4，8，16等等，这样在称量同等重量下使用的砝码数量最少，只使用7个砝码就可以称量1－127的重量。&#8221; <br>Hill：&#8220;No, you are wrong&#8221;。 <br>Oren：&#8220;难道还有更好的方法？2进制是最优的，这一点是可以证明的&#8221; <br>Hill：&#8220;如果只允许砝码放在天平的一端，那么你说的是对的，可是并没有人限制我们可以在天平的两端放置砝码。所以可以有更好的方法。如可以设计砝码重量为1，3，9，27，81，只用5个砝码就可以称量1－121&#8221;。 <br>Oren：&#8220;原来是3进制，那怎么称重呢? 如100克重量？&#8221;<br>Hill：&#8220;在天平的左端放上重物，再放上砝码9，右端放砝码1, 27, 81&#8221;。<br>Oren：&#8220;嗯，可这是怎么算出来的呢？&#8221;<br>Hill：&#8220;It&#8217;s your business&#8221;。<br>现在，作为Oren的朋友，请你设计一个程序来计算在这种砝码下应如何称量。<br>
<h3>Input:</h3>
输入包括多个整数，每个数n占据一行，代表要称重的重量。0 &lt; n &lt;= 1000000000。
<h3>Output:</h3>
对于每个输入的整数，计算当此重量放置在天平左端时，应如何安排3进制的砝码，使天平平衡。每个结果输出一行，输出格式如例子所示，每个数字后面一个空格，如某一侧没有砝码，则输出0，多个砝码按重量升序排列。
<h3>Sample Input:</h3>
<pre>100
30
</pre>
<h3>Sample Output:</h3>
<pre>9 left, 1 27 81 right.
0 left, 3 27 right.
</pre>
----------<br>题目很经典<br>不要误解题意，注意n的范围，<br>不是搜索。 点下面的加号打开代码<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img id=Code_Closed_Image_154602 onclick="this.style.display='none'; Code_Closed_Text_154602.style.display='none'; Code_Open_Image_154602.style.display='inline'; Code_Open_Text_154602.style.display='inline';" height=16 src="http://www.cppblog.com/Images/OutliningIndicators/ContractedBlock.gif" width=11 align=top><img id=Code_Open_Image_154602 style="DISPLAY: none" onclick="this.style.display='none'; Code_Open_Text_154602.style.display='none'; Code_Closed_Image_154602.style.display='inline'; Code_Closed_Text_154602.style.display='inline';" height=16 src="http://www.cppblog.com/Images/OutliningIndicators/ExpandedBlockStart.gif" width=11 align=top><span id=Code_Closed_Text_154602 style="BORDER-RIGHT: #808080 1px solid; BORDER-TOP: #808080 1px solid; BORDER-LEFT: #808080 1px solid; BORDER-BOTTOM: #808080 1px solid; BACKGROUND-COLOR: #ffffff">别人的代码</span><span id=Code_Open_Text_154602 style="DISPLAY: none"><br><!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--><span style="COLOR: #000000">#include</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">stdio.h</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000"><br></span><span style="COLOR: #0000ff">int</span><span style="COLOR: #000000">&nbsp;left[</span><span style="COLOR: #000000">20</span><span style="COLOR: #000000">],right[</span><span style="COLOR: #000000">20</span><span style="COLOR: #000000">];<br></span><span style="COLOR: #0000ff">int</span><span style="COLOR: #000000">&nbsp;main()<br>{<br>&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">int</span><span style="COLOR: #000000">&nbsp;n;<br>&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">while</span><span style="COLOR: #000000">(scanf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">%d</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">,</span><span style="COLOR: #000000">&amp;</span><span style="COLOR: #000000">n)</span><span style="COLOR: #000000">==</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">)<br>&nbsp;&nbsp;&nbsp;&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">int</span><span style="COLOR: #000000">&nbsp;d</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">,i</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">,j</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">,k;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">while</span><span style="COLOR: #000000">(n)<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">while</span><span style="COLOR: #000000">(</span><span style="COLOR: #000000">!</span><span style="COLOR: #000000">(n</span><span style="COLOR: #000000">%</span><span style="COLOR: #000000">3</span><span style="COLOR: #000000">))&nbsp;{n</span><span style="COLOR: #000000">/=</span><span style="COLOR: #000000">3</span><span style="COLOR: #000000">;&nbsp;d</span><span style="COLOR: #000000">*=</span><span style="COLOR: #000000">3</span><span style="COLOR: #000000">;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(n</span><span style="COLOR: #000000">%</span><span style="COLOR: #000000">3</span><span style="COLOR: #000000">==</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">){right[i</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">]</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">d;&nbsp;n</span><span style="COLOR: #000000">--</span><span style="COLOR: #000000">;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">else</span><span style="COLOR: #000000">&nbsp;</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(n</span><span style="COLOR: #000000">%</span><span style="COLOR: #000000">3</span><span style="COLOR: #000000">==</span><span style="COLOR: #000000">2</span><span style="COLOR: #000000">)&nbsp;{left[j</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">]</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">d;&nbsp;n</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(j</span><span style="COLOR: #000000">==</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">)&nbsp;</span><span style="COLOR: #0000ff">for</span><span style="COLOR: #000000">(k</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">;k</span><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">j;k</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">)&nbsp;printf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">%d&nbsp;</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">,left[k]);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">else</span><span style="COLOR: #000000">&nbsp;</span><span style="COLOR: #0000ff">for</span><span style="COLOR: #000000">(k</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">1</span><span style="COLOR: #000000">;k</span><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">j;k</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">)&nbsp;printf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">%d&nbsp;</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">,left[k]);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">left,&nbsp;</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">for</span><span style="COLOR: #000000">(k</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">;k</span><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">i;k</span><span style="COLOR: #000000">++</span><span style="COLOR: #000000">)&nbsp;printf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">%d&nbsp;</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">,right[k]);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printf(</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">right.\n</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">);<br>&nbsp;&nbsp;&nbsp;&nbsp;}<br>&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="COLOR: #0000ff">return</span><span style="COLOR: #000000">&nbsp;</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">;<br>}<br></span></span></div>
<br></div>
<img src ="http://www.cppblog.com/luyulaile/aggbug/90523.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.cppblog.com/luyulaile/" target="_blank">luis</a> 2009-07-19 15:46 <a href="http://www.cppblog.com/luyulaile/archive/2009/07/19/90523.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>