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一个算法问题

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悬赏园豆：20 [已关闭问题]
请教一个算法问题<BR>这样一个数组如：0 1 2 3<BR>要循环执行.依次执行 0 1 2 3但到最后一个(即3)后，执行顺序变成 3 2 1 0，（结果就像0 1 2 3 2 1 0 1 2 3 2 1 0...）<BR>这样的一个循环有没有相应的算法？<BR>自己写了一个(javascript)但感觉比较傻<BR> <DIV class=cnblogs_code><!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--><SPAN style="COLOR: #000000">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN style="COLOR: #0000ff">var</SPAN><SPAN style="COLOR: #000000">&nbsp;l&nbsp;</SPAN><SPAN style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #0000ff">true</SPAN><SPAN style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN style="COLOR: #0000ff">function</SPAN><SPAN style="COLOR: #000000">&nbsp;play()&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$(</SPAN><SPAN style="COLOR: #000000">'</SPAN><SPAN style="COLOR: #000000">#key</SPAN><SPAN style="COLOR: #000000">'</SPAN><SPAN style="COLOR: #000000">).val(aIndex);<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;active(aIndex);<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN style="COLOR: #0000ff">if</SPAN><SPAN style="COLOR: #000000">&nbsp;(l)&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;(aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">-</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">1</SPAN><SPAN style="COLOR: #000000">)&nbsp;</SPAN><SPAN style="COLOR: #000000">%</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">4</SPAN><SPAN style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN style="COLOR: #0000ff">if</SPAN><SPAN style="COLOR: #000000">&nbsp;(aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">&lt;=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">0</SPAN><SPAN style="COLOR: #000000">)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;l&nbsp;</SPAN><SPAN style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">!</SPAN><SPAN style="COLOR: #000000">l;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&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">else</SPAN><SPAN style="COLOR: #000000">&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;(aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">+</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">1</SPAN><SPAN style="COLOR: #000000">)&nbsp;</SPAN><SPAN style="COLOR: #000000">%</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">4</SPAN><SPAN style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN style="COLOR: #0000ff">if</SPAN><SPAN style="COLOR: #000000">&nbsp;(aIndex&nbsp;</SPAN><SPAN style="COLOR: #000000">&gt;=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">3</SPAN><SPAN style="COLOR: #000000">)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;l&nbsp;</SPAN><SPAN style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">!</SPAN><SPAN style="COLOR: #000000">l;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<BR>还有个想法是可以把0 1 2 3组合成0 1 2 3 + 2 1(原始数组加上去掉首尾的数组)，即012321这样只要顺序执行就行了<BR></SPAN></DIV>
PENGHAO-X的主页 PENGHAO-X | 初学一级 | 园豆：20
提问于：2008-08-27 12:52
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其他回答(2)
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你那个想法就很好啊 重复执行 0 1 2 3 2 1
丁学 | 园豆：18730 (专家六级) | 2008-08-27 14:03
0
设置两个堆栈，3210进栈 然后出栈的时候输出，再进另外一个栈 如此循环 在出栈的时候输出
Jesse Jiang | 园豆：205 (菜鸟二级) | 2008-08-28 22:03
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Next
好像取模运算比较费时间的。我觉得还是这样好，逻辑挺清爽的啊，用其他方式，可能会不便于阅读。

陛下 | 园豆：3938 (老鸟四级) | 2008-09-07 03:14
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