Fast Boolean matrix multiplication for highly clustered data

In English We consider the problem of computing the product of two
n×n Boolean matrices A and B. For an n×n Boolean matrix C, let GC
be the complete weighted graph on the rows of C where the weight of an
edge between two rows is equal to its Hamming distance, i.e., the number
of entries in the first row having values different from the corresponding
entries in the second one. Next, letMWT(C) be the weight of a minimum
weight spanning tree of GC. We show that the product of A with B as
well as the so called witnesses of the product can be computed in time
(n(n + min{MWT(A),MWT(Bt)}))
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