Ah. Another Data mining question. Please note that your fundamental problem, set cover optimization, is known to be NP-hard.

That said, take a look at Comparing two arrays and other posts by same OP.

500 by 75 sounds too small to be a real-life problem. But if it is, could you please share with us the focus area of your research?

In reply to Re: Groups of Objects with Common Attributes by Anonymous Monk
in thread Groups of Objects with Common Attributes by Dev Null

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