Computing Best and Worst Shortcuts of Graphs Embedded in Metric Spaces
Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review
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Computing Best and Worst Shortcuts of Graphs Embedded in Metric Spaces. / Wulff-Nilsen, Christian; Luo, Jun.
Algorithms and Computation: 19th International Symposium, ISAAC 2008, Gold Coast, Australia, December 15-17, 2008, Proceedings. ed. / Seok-Hee Hong; Hiroshi Nagamochi; Takuro Fukunaga. Springer, 2008. p. 764-775 (Lecture notes in computer science; No. 5369).Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review
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TY - GEN
T1 - Computing Best and Worst Shortcuts of Graphs Embedded in Metric Spaces
AU - Wulff-Nilsen, Christian
AU - Luo, Jun
N1 - Conference code: 19
PY - 2008
Y1 - 2008
N2 - Given a graph embedded in a metric space, its dilation is the maximum over all distinct pairs of vertices of the ratio between their distance in the graph and the metric distance between them. Given such a graph G with n vertices and m edges and consisting of at most two connected components, we consider the problem of augmenting G with an edge such that the resulting graph has minimum dilation. We show that we can find such an edge in O((n^4*log n)/m^{0.5}) time using linear space which solves an open problem of whether a linear-space algorithm with o(n^4) running time exists. We show that O(n^2*log n) time is achievable if G is a simple path or the union of two vertex-disjoint simple paths. Finally, we show how to find an edge that maximizes the dilation of the resulting graph in O(n^3) time with O(n^2) space and in O(n^3*log n) time with linear space.
AB - Given a graph embedded in a metric space, its dilation is the maximum over all distinct pairs of vertices of the ratio between their distance in the graph and the metric distance between them. Given such a graph G with n vertices and m edges and consisting of at most two connected components, we consider the problem of augmenting G with an edge such that the resulting graph has minimum dilation. We show that we can find such an edge in O((n^4*log n)/m^{0.5}) time using linear space which solves an open problem of whether a linear-space algorithm with o(n^4) running time exists. We show that O(n^2*log n) time is achievable if G is a simple path or the union of two vertex-disjoint simple paths. Finally, we show how to find an edge that maximizes the dilation of the resulting graph in O(n^3) time with O(n^2) space and in O(n^3*log n) time with linear space.
U2 - 10.1007/978-3-540-92182-0_67
DO - 10.1007/978-3-540-92182-0_67
M3 - Article in proceedings
T3 - Lecture notes in computer science
SP - 764
EP - 775
BT - Algorithms and Computation
A2 - Hong, Seok-Hee
A2 - Nagamochi, Hiroshi
A2 - Fukunaga, Takuro
PB - Springer
Y2 - 15 December 2008 through 17 December 2008
ER -
ID: 9617006