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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> spike [mailto:spike66@att.net] <br><b><span style='color:#1F497D'>>…</span></b></span><o:p></o:p></p></div></div><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'>>…</span><span style='color:black'>Ja. A few years ago, I wrote an excel script which solves sudokus. It can take a couple days to solve one. I am not arguing that it is an efficient algorithm. {8^D I would argue however that the act of writing those kinds of scripts is good for the brain.</span><span style='color:#1F497D'> </span><span style='color:black'>spike</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'>I left out a critically important detail. The usual 9x9 sudokus can be solved by this algorithm in about a half a second usually. I don’t remember the exact score, but I think it was generating and solving them about 150-ish per minute.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'>This algorithm can take up to 204x204 sudokus, and those biggies take a couple days each to solve, as I recall. It has been a long time since I played with it, but I can find out the date, for I remember we had a huge solar event just as I was finishing that, and the huge X11 flare that took everyone by surprise, so I was immediately distracted by that and was too busy to mess with Sudoku for the next several weeks because of the flare. Then I never got back to it, but as I vaguely recall, it was about 8 yrs ago. I should resurrect that code to see if modern computers can solve it faster than the machine I was using back then, which was already outdated back then.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#1F497D'>spike<o:p></o:p></span></p></div></body></html>