2005 International Conference on Analysis of Algorithms
Conrado Martínez (ed.)
DMTCS Conference Volume AD (2005), pp. 287296
author:  Hadas Shachnai and Lisa Zhang 

title:  The master ring problem 
keywords:  Master ring, shortest common supersequence, optical networks, exact algorithms. 
abstract: 
We consider the master ring problem (MRP) which
often arises in optical network design. Given a network
which consists of a collection of interconnected rings
R
,
1
…
,
R
, with
K
n
,
1
…
,
n
distinct nodes, respectively, we need to find an
ordering of the nodes in the network that respects the
ordering of every individual ring, if one exists. Our main
result is an exact algorithm for MRP whose running time
approaches
K
Q·∏
for some polynomial
k=1
K
(n
k
/√
2
)
Q
, as the
n
values become large. For the ring clearance
problem, a special case of practical interest, our
algorithm achieves this running time for rings of
any size
k
n
. This yields the first nontrivial improvement, by
factor of
k
≥2
(2√
, over the running time of the naive algorithm, which
exhaustively enumerates all
2
)
K
≈ (2.82)
K
∏
possible solutions.
k=1
K
(2n
k
)

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reference:  Hadas Shachnai and Lisa Zhang (2005), The master ring problem, in 2005 International Conference on Analysis of Algorithms, Conrado Martínez (ed.), Discrete Mathematics and Theoretical Computer Science Proceedings AD, pp. 287296 
bibtex:  For a corresponding BibTeX entry, please consider our BibTeXfile. 
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