Max-stretch reduction for tree spanners

Sökning: WFRF:(Okita K) > Max-stretch reducti...

Iwama, K (författare)

Lingas, Andrzej (författare): Lund University,Lunds universitet,Data Vetenskap,Naturvetenskapliga fakulteten,Computer Science,Faculty of Science

Okita, M (författare)

(creator_code:org_t)

Berlin, Heidelberg : Springer Berlin Heidelberg, 2005
2005
Engelska.
Ingår i: Algorithms and Data Structures / Lecture Notes in Computer Science. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0302-9743 .- 1611-3349. - 9783540281016 ; 3608, s. 122-133

Relaterad länk:: http://dx.doi.org/10...; visa fler...; http://www.cs.au.dk/...; https://lup.lub.lu.s...; https://doi.org/10.1...; visa färre...

Abstract Ämnesord

Stäng

A tree t-spanner T of a graph G is a spanning tree of G whose max-stretch is t, i.e., the distance between any two vertices in T is at most t times their distance in G. If G has a tree t-spanner but not a tree (t - 1)-spanner, then G is said to have max-stretch of t. In this paper, we study the Max-Stretch Reduction Problem: for an unweighted graph G = (V, E), find a set of edges not in E originally whose insertion into G can decrease the max-stretch of G. Our results are as follows: (i) For a ring graph, we give a linear-time algorithm which inserts k edges improving the max-stretch optimally. (ii) For a grid graph, we give a nearly optimal max-stretch reduction algorithm which preserves the structure of the grid. (iii) In the general case, we show that it is NP-hard to decide, for a given graph G and its spanning tree of max-stretch t, whether or not one-edge insertion can decrease the max-stretch to t- 1. (iv) Finally, we show that the max-stretch of an arbitrary graph on n vertices can be reduced to s' >= 2 by inserting O(n/s') edges, which can be determined in linear time, and observe that this number of edges is optimal up to a constant.

Om ämnet

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.