Abstract
Let T be a tree with n vertices embedded in a metric space. We consider the problem of adding one edge to T to minimize the radius of the resulting graph.
For the continuous version of the problem where a center may be a point in the interior of an edge of the graph we give a linear time algorithm. In the case when the center is restricted to lie on a vertex, the discrete version, we give an \(O(n \log n)\) expected time algorithm.
Previously linear-time algorithms were known for the special case when the input graph is a path.
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Gudmundsson, J., Sha, Y.: Augmenting graphs to minimize the radius. Manuscript (2021)
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Gudmundsson, J., Sha, Y. (2021). Algorithms for Radius-Optimally Augmenting Trees in a Metric Space. In: Lubiw, A., Salavatipour, M., He, M. (eds) Algorithms and Data Structures. WADS 2021. Lecture Notes in Computer Science(), vol 12808. Springer, Cham. https://doi.org/10.1007/978-3-030-83508-8_33
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