[转贴]扩展矩形顶点删除法（sd）

justfun

<P>&nbsp;</P>
<P><FONT face="Courier New">原理是在矩形顶点删除法的基础上，对于一个顶点可以变为一个条块<BR>*-----------------------------------------------*<BR>|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp; D1&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>|&nbsp;&nbsp;&nbsp; A&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp; D2&nbsp;&nbsp;&nbsp; *&nbsp;&nbsp;&nbsp; *|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp; D3&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>|---------------+---------------+---------------|<BR>|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&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; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>|&nbsp;&nbsp;&nbsp; B&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; C&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>|---------------+---------------+---------------|<BR>|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&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; .&nbsp;&nbsp;&nbsp; .&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; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .&nbsp;&nbsp;&nbsp; .|<BR>*-----------------------------------------------*<BR>&nbsp; 在上图中，某数字在第一列仅出现在A/B位置上，在第四列仅在C-(D1D2D3)位置出现。<BR>图中*位置不是该数字。 原因是： <BR>&nbsp; 1) A=N时，&nbsp; *位置显然不能为 N<BR>&nbsp; 2) A不为N时， B=N, C不能为N, D1D2D3 中必定有N,所以D1D2D3所在九宫格中其他位置不能为N</FONT></P>
<P><FONT face="Courier New">ps：这绝对是个好贴。值得研究。</P></FONT>

[ 本帖最后由 justfun 于 2008-5-14 23:26 编辑 ]

justfun

<FONT face="Courier New">例题<BR>*---------------------------------*<BR>|9&nbsp; <FONT color=#0000ff><STRONG><FONT color=#000000>1</FONT>&nbsp;</STRONG></FONT>&nbsp; 34 |8&nbsp; <FONT style="BACKGROUND-COLOR: #ff0000">34</FONT>&nbsp; <STRONG>5</STRONG>&nbsp; | 2&nbsp;&nbsp; <STRONG>7&nbsp;</STRONG>&nbsp; <STRONG>6</STRONG> |<BR>|<FONT style="BACKGROUND-COLOR: #008000">34</FONT> <STRONG>7&nbsp;</STRONG>&nbsp; 2&nbsp; |<FONT style="BACKGROUND-COLOR: #008000"><STRONG>6</STRONG>&nbsp; 134 13</FONT> | 8&nbsp;&nbsp; <STRONG>5</STRONG>&nbsp;&nbsp; 9 |<BR>|6&nbsp; 8&nbsp;&nbsp; 5&nbsp; |9&nbsp; <STRONG>2&nbsp;</STRONG>&nbsp; 7&nbsp; | 4&nbsp;&nbsp; 3&nbsp;&nbsp; 1 |<BR>|----------+----------+-----------|<BR>|47 5&nbsp;&nbsp; 14 |2&nbsp;&nbsp;17&nbsp; 6&nbsp; |<STRONG>&nbsp;3</STRONG>&nbsp;&nbsp; 9&nbsp;&nbsp; &nbsp;<STRONG>8</STRONG>|<BR>|<FONT style="BACKGROUND-COLOR: #008000">37</FONT> 6&nbsp;&nbsp; <STRONG>8</STRONG>&nbsp; |<STRONG>4&nbsp;</STRONG> <FONT style="BACKGROUND-COLOR: #008000">37</FONT>&nbsp; 9&nbsp; | <STRONG>1</STRONG>&nbsp;&nbsp; 2&nbsp;&nbsp; 5 |<BR>|<STRONG>2&nbsp;</STRONG> 9&nbsp;&nbsp; 13 |<STRONG>5</STRONG>&nbsp; 8&nbsp;&nbsp; 13 | 6&nbsp;&nbsp; 4&nbsp;&nbsp; 7 |<BR>|----------|----------|-----------|<BR>|<STRONG>8&nbsp;</STRONG> 3&nbsp;&nbsp; 7&nbsp; |1&nbsp; <STRONG>9&nbsp;&nbsp; 2</STRONG>&nbsp; | 5&nbsp;&nbsp; 6&nbsp;&nbsp; 4 |<BR>|<STRONG>5&nbsp;</STRONG> 4&nbsp;&nbsp; <STRONG>9</STRONG>&nbsp; |3&nbsp; 6&nbsp;&nbsp; <STRONG>8</STRONG>&nbsp; | 7&nbsp;&nbsp; 1&nbsp;&nbsp; 2 |<BR>|1&nbsp; 2&nbsp;&nbsp; <STRONG>6&nbsp;</STRONG> |7&nbsp; 5&nbsp;&nbsp; 4&nbsp; | 9&nbsp;&nbsp; 8&nbsp;&nbsp; <STRONG>3 </STRONG>|<BR>*---------------------------------*</FONT>
<P><FONT face="Courier New">红色位置排除数字3。</FONT></P>

luo

不懂。

justfun

这个帖子，我如果不转，我会觉得很可惜。对于，爱好数独的人来说，看到这个帖子，眼睛会一亮。

老徐最可爱

没看懂！

justfun

<P>

原帖由 <I>老徐最可爱</I> 于 2008-5-9 22:15 发表 <A href="http://bbs.xujinglei.org/redirect.php?goto=findpost&amp;pid=439854&amp;ptid=33798" target=_blank><IMG alt="" src="http://bbs.xujinglei.org/images/common/back.gif" border=0></A> 没看懂！

</P>
<P>看一下例题不难理解的：</P>
<P>&nbsp; 1&nbsp;&nbsp;&nbsp;&nbsp;2&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 4&nbsp;&nbsp;&nbsp;&nbsp; 5&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 6&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 7&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 8&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 9</P>
<P><FONT face="Courier New">*---------------------------------*<BR>|9&nbsp; <FONT color=#0000ff><STRONG><FONT color=#000000>1</FONT>&nbsp;</STRONG></FONT>&nbsp; 34 |8&nbsp; <FONT style="BACKGROUND-COLOR: #ff0000">34</FONT>&nbsp; <STRONG>5</STRONG>&nbsp; | 2&nbsp;&nbsp; <STRONG>7&nbsp;</STRONG>&nbsp; <STRONG>6</STRONG> |A<BR>|<FONT style="BACKGROUND-COLOR: #008000">34</FONT> <STRONG>7&nbsp;</STRONG>&nbsp; 2&nbsp; |<FONT style="BACKGROUND-COLOR: #008000"><STRONG>6</STRONG>&nbsp; 134 13</FONT> | 8&nbsp;&nbsp; <STRONG>5</STRONG>&nbsp;&nbsp; 9 |B<BR>|6&nbsp; 8&nbsp;&nbsp; 5&nbsp; |9&nbsp; <STRONG>2&nbsp;</STRONG>&nbsp; 7&nbsp; | 4&nbsp;&nbsp; 3&nbsp;&nbsp; 1 |C<BR>|----------+----------+-----------|<BR>|47 5&nbsp;&nbsp; 14 |2&nbsp;&nbsp;17&nbsp; 6&nbsp; |<STRONG>&nbsp;3</STRONG>&nbsp;&nbsp; 9&nbsp;&nbsp;&nbsp;<STRONG>8 </STRONG>|D<BR>|<FONT style="BACKGROUND-COLOR: #008000">37</FONT> 6&nbsp;&nbsp; <STRONG>8</STRONG>&nbsp; |<STRONG>4&nbsp;</STRONG> <FONT style="BACKGROUND-COLOR: #008000">37</FONT>&nbsp; 9&nbsp; | <STRONG>1</STRONG>&nbsp;&nbsp; 2&nbsp;&nbsp; 5 |E<BR>|<STRONG>2&nbsp;</STRONG> 9&nbsp;&nbsp; 13 |<STRONG>5</STRONG>&nbsp; 8&nbsp;&nbsp; 13 | 6&nbsp;&nbsp; 4&nbsp;&nbsp; 7 |F<BR>|----------|----------|-----------|<BR>|<STRONG>8&nbsp;</STRONG> 3&nbsp;&nbsp; 7&nbsp; |1&nbsp; <STRONG>9&nbsp;&nbsp; 2</STRONG>&nbsp; | 5&nbsp;&nbsp; 6&nbsp;&nbsp; 4 |G<BR>|<STRONG>5&nbsp;</STRONG> 4&nbsp;&nbsp; <STRONG>9</STRONG>&nbsp; |3&nbsp; 6&nbsp;&nbsp; <STRONG>8</STRONG>&nbsp; | 7&nbsp;&nbsp; 1&nbsp;&nbsp; 2 |H<BR>|1&nbsp; 2&nbsp;&nbsp; <STRONG>6&nbsp;</STRONG> |7&nbsp; 5&nbsp;&nbsp; 4&nbsp; | 9&nbsp;&nbsp; 8&nbsp;&nbsp; <STRONG>3 </STRONG>|I</FONT><FONT face="Courier New"><BR>*---------------------------------*</FONT> </P>
<P><FONT face="Courier New">这个题目是说，用标绿色的位置，来排除标红色的A5候选数3。</FONT></P>
<P><FONT face="Courier New">若E5=3，显然A5≠3；</FONT></P>
<P><FONT face="Courier New">若E1=3，则B1≠3，考察B行，3∈B5B6，那么在第2宫内，应排除其它位置的3，也有A5≠3。</FONT></P>
<P><FONT face="Courier New">A5≠3就是这样来的。</FONT></P>
<P><FONT face="Courier New">很简单吧。</FONT></P>
<P><FONT face="Courier New" color=red>其实数独很简单~~~</FONT></P>

[ 本帖最后由 justfun 于 2008-5-10 09:25 编辑 ]

justfun

关键是应用问题，具体作题的时候，不一定能看出来~~~

﹎¨瑩、℡

··  又是让人头晕的题目

justfun

<P>昨晚做了1题，ms可用这个方法~~~</P>