Nick Kostirya wrote: > > If one imagines 'in a matrix way', the friends-chart turns into a > matrix with 1 and 0 values. Next, the matrix is multiplied to vector > (how many apples each friend gives to each one). > > In a word, it's simple. However, there's a question: is there any > optimization for such actions ? I'm afraid, this matrix will gobble > all the memory . > Perhaps a sparse representation of your matrix, using $. , would be one optimization to consider here.
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