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[ 本帖最后由 〇〇 于 2015-12-16 16:46 编辑 ]
[quote][size=2][color=#999999]lugionline 发表于 2015-12-4 14:03[/color] [url=forum.php?mod=redirect&goto=findpost&pid=23121334&ptid=1931570][img]static/image/common/back.gif[/img][/url][/size]
不需要太快,你码这些SQL代码都不止几秒了,略作改进就可以更快
In[1]:= K = 4;
[/quote]
In[27]:= (
x=Select[Tuples[{-1, 0, 1}, 4], Total[#] > 0 &];
x2=Select[Tuples[x, 2], Min[Total[#,1]] >= -1 &];
x2t=Total[x2,{2}];
x3=Table[x2t[[i]]+x[[j]],{i,Length[x2t]},{j,Length[x]}];
x4=Flatten[x3,1];
x5=Select[x4,Min[#]>=0 &];
x6=Table[x5[[i]]+x[[j]],{i,Length[x5]},{j,Length[x]}];
Length@Select[Flatten[x6,1],Min[#]>0 &])//Timing
Out[27]= {2.453, 294879}
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