A note on blocking visibility between points
نویسندگان
چکیده
Given a finite point set P in the plane, let b(P ) be the smallest number of points q1, q2, . . . not belonging to P which together block all visibilities between elements of P , that is, every open segment whose endpoints belong to P contains at least one point qi. Let b(n) denote the minimum of b(P ) over all n-element point sets P , with no three points on the same line. It is known that 2n − 3 ≤ b(n) ≤ n2 √ log , where c is an absolute constant. Here we raise the lower bound to (
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