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An Approximation Problem for the Multi-Via Assignment Problem

We consider the multi-via assignment problem for multilayered printed circuit board routing. An efficient approximation algorithm for this problem is presented. The algorithm is of (low) polynomial time complexity and guarantees solutions with no more than 3 * OPT via columns, where OPT is the number of via columns in an optimal solution. Several issues relating to the computational complexity of via and multi-via assignment problems are also discussed.