note
hv
<p>Sticking with the bitstring concept, I think rather that you are looking for a subset of <i>n</i> bitstrings such that the bitwise-OR of the bitstrings has only <i>n</i> distinct bits set.</p>
<p>Note that some or all of those bitstrings may have fewer than <i>n</i> bits set; you may even have two bitstrings that have no bit set in common in a qualifying subset (though you'd need a minimum of 4 elements in the subset to avoid it being further decomposable).</p>
<p>Hugo</p>
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