Cutwidth: Obstructions and Algorithmic Aspects
Cutwidth is one of the classic layout parameters for graphs. It measures how well one can order the vertices of a graph in a linear manner, so that the maximum number of edges between any prefix and its complement suffix is minimized. As graphs of cutwidth at most k are closed under taking immersion...
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| Veröffentlicht in: | Algorithmica Jg. 81; H. 2; S. 557 - 588 |
|---|---|
| Hauptverfasser: | , , , , |
| Format: | Journal Article |
| Sprache: | Englisch |
| Veröffentlicht: |
New York
Springer US
01.02.2019
Springer Nature B.V Springer Verlag |
| Schlagworte: | |
| ISSN: | 0178-4617, 1432-0541 |
| Online-Zugang: | Volltext |
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| Zusammenfassung: | Cutwidth is one of the classic layout parameters for graphs. It measures how well one can order the vertices of a graph in a linear manner, so that the maximum number of edges between any prefix and its complement suffix is minimized. As graphs of cutwidth at most
k
are closed under taking immersions, the results of Robertson and Seymour imply that there is a finite list of minimal immersion obstructions for admitting a cut layout of width at most
k
. We prove that every minimal immersion obstruction for cutwidth at most
k
has size at most
2
O
(
k
3
log
k
)
. As an interesting algorithmic byproduct, we design a new fixed-parameter algorithm for computing the cutwidth of a graph that runs in time
2
O
(
k
2
log
k
)
·
n
, where
k
is the optimum width and
n
is the number of vertices. While being slower by a
log
k
-factor in the exponent than the fastest known algorithm, given by Thilikos et al. (J Algorithms 56(1):1–24,
2005
; J Algorithms 56(1):25–49,
2005
), our algorithm has the advantage of being simpler and self-contained; arguably, it explains better the combinatorics of optimum-width layouts. |
|---|---|
| Bibliographie: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 |
| ISSN: | 0178-4617 1432-0541 |
| DOI: | 10.1007/s00453-018-0424-7 |