On the minimum local-vertex-connectivity augmentation in graphs
β Scribed by Hiroshi Nagamochi; Toshimasa Ishii
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 179 KB
- Volume
- 129
- Category
- Article
- ISSN
- 0166-218X
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β¦ Synopsis
Given a graph G and target values r(u; v) prescribed for each pair of vertices u and v, we consider the problem of augmenting G by a smallest set F of new edges such that the resulting graph G+F has at least r(u; v) internally disjoint paths between each pair of vertices u and v. We show that the problem is NP-hard even if for some constant k ΒΏ 2 G is (k -1)-vertex-connected and r(u; v) β {0; k} holds for u; v β V . We then give a linear time algorithm which delivers a 3 2 -approximation solution to the problem with a connected graph G and r(u; v) β {0; 2}, u; v β V .
π SIMILAR VOLUMES
Let G be a connected k-regular vertex-transitive graph on n vertices. For S V(G) let d(S) denote the number of edges between S and V(G)"S. We extend results of Mader and Tindell by showing that if d(S)< 2 9 (k+1) 2 for some S V(G) with 1 3 (k+1) |S| 1 2 n, then G has a factor F such that GΓE(F ) is