A Polynomial Time Approximation Scheme for Minimum Routing Cost Spanning Trees

Tang, Chuan Yi
Ravi, R.
Chao, Kun-Mao
Bafna, Vineet
Lancia, Giuseppe
Wu, Bang Ye

Abstract

Abstract Given an undirected graph with nonnegative costs on the edges, the routing cost of any of its spanning trees is the sum over all pairs of vertices of the cost of the path between the pair in the tree. Finding a spanning tree of minimum routing cost is NP-hard, even when the costs obey the triangle inequality. We show that the general case is in fact reducible to the metric case and present a polynomial-time approximation scheme valid for both versions of the problem. In particular, we show how to build a spanning tree of an n-vertex weighted graph with routing cost at most (1 + epsilon) of the the minimum in time O(n ^ O(1/epsilon)). Besides the obvious connection to network design, trees with small routing cost also find application in the construction of good multiple sequence alignments in computational biology.

Keywords

tree
spanning tree
routing cost

Notes

Important. Shows how to build a bounded cost spanning tree if a fixed amount of time.

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Bibtex

 @article{wu.tang_poly98,
author = "B. Y. Wu and G. Lancia and V. Bafna and K. M. Chao and R. Ravi and C. Y. Tang",
title = "A polynomial time approximation scheme for minimum routing cost spanning trees",
journal="SIAM Journal on Computing",
number="3",
volume="29",
pages="761--778",
year="2000"
}

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