Research output: Contribution to journal › Article › peer-review
Min-weight double-tree shortcutting for Metric TSP: Bounding the approximation ratio. / Deineko, Vladimir; Tiskin, Alexander.
In: Electronic Notes in Discrete Mathematics, Vol. 32, No. C, 15.03.2009, p. 19-26.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Min-weight double-tree shortcutting for Metric TSP: Bounding the approximation ratio
AU - Deineko, Vladimir
AU - Tiskin, Alexander
PY - 2009/3/15
Y1 - 2009/3/15
N2 - The Metric Traveling Salesman Problem (TSP) is a classical NP-hard optimization problem. The double-tree shortcutting method for Metric TSP yields an exponentially-sized space of TSP tours, each of which approximates the optimal solution within at most a factor of 2. We consider the problem of finding among these tours the one that gives the closest approximation, i.e. the minimum-weight double-tree shortcutting. Previously, we gave an efficient algorithm for this problem, and carried out its experimental analysis. In this paper, we address the related question of the worst-case approximation ratio for the minimum-weight double-tree shortcutting method. In particular, we give lower bounds on the approximation ratio in some specific metric spaces: the ratio of 2 in the discrete shortest path metric, 1.622 in the planar Euclidean metric, and 1.666 in the planar Minkowski metric. The first of these lower bounds is tight; we conjecture that the other two bounds are also tight, and in particular that the minimum-weight double-tree method provides a 1.622-approximation for planar Euclidean TSP. © 2009 Elsevier B.V. All rights reserved.
AB - The Metric Traveling Salesman Problem (TSP) is a classical NP-hard optimization problem. The double-tree shortcutting method for Metric TSP yields an exponentially-sized space of TSP tours, each of which approximates the optimal solution within at most a factor of 2. We consider the problem of finding among these tours the one that gives the closest approximation, i.e. the minimum-weight double-tree shortcutting. Previously, we gave an efficient algorithm for this problem, and carried out its experimental analysis. In this paper, we address the related question of the worst-case approximation ratio for the minimum-weight double-tree shortcutting method. In particular, we give lower bounds on the approximation ratio in some specific metric spaces: the ratio of 2 in the discrete shortest path metric, 1.622 in the planar Euclidean metric, and 1.666 in the planar Minkowski metric. The first of these lower bounds is tight; we conjecture that the other two bounds are also tight, and in particular that the minimum-weight double-tree method provides a 1.622-approximation for planar Euclidean TSP. © 2009 Elsevier B.V. All rights reserved.
KW - approximation algorithms
KW - double-tree shortcutting
KW - Metric TSP
UR - http://www.scopus.com/inward/record.url?scp=61549137199&partnerID=8YFLogxK
U2 - 10.1016/j.endm.2009.02.004
DO - 10.1016/j.endm.2009.02.004
M3 - Article
AN - SCOPUS:61549137199
VL - 32
SP - 19
EP - 26
JO - Electronic Notes in Discrete Mathematics
JF - Electronic Notes in Discrete Mathematics
SN - 1571-0653
IS - C
ER -
ID: 127710302