An Approximation Algorithm for the Minimum Weight Vertex-Connectivity Problem in Complete Graphs with Sharpened Triangle Inequality

نویسندگان

  • Alessandro Ferrante
  • Mimmo Parente
چکیده

Consider a complete graph G with the edge weights satisfying the β-sharpened triangle inequality: weight(u, v) ≤ β(weight(u, x)+ weight(x, v)), for 1/2 ≤ β < 1. We study the NP-hard problem of finding a minimum weight spanning subgraph of G which is k-vertex-connected, k ≥ 2, and give a detailed analysis of an approximation quadratic-time algorithm whose performance ratio is β 1−β . The algorithm is derived from the one presented by Böckenhauer et al. in [3] for the k-edge connectivity problem on graphs satisfying the βsharpened triangle inequality.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

On the Hardness of Constructing Minimal 2-Connected Spanning Subgraphs in Complete Graphs with Sharpened Triangle Inequality

In this paper we investigate the problem of finding a 2-connected spanning subgraph of minimal cost in a complete and weighted graph G. This problem is known to be APX-hard, for both the edge and the vertex connectivity case. Here we prove that theAPX-hardness still holds even if one restricts the edge costs to an interval [1, 1+ε], for an arbitrary small ε > 0. This result implies the first ex...

متن کامل

Finding k-Connected Subgraphs with Minimum Average Weight

We consider the problems of finding k-connected spanning subgraphs with minimum average weight. We show that the problems are NP-hard for k > 1. Approximation algorithms are given for four versions of the minimum average edge weight problem: 1. 3-approximation for k-edge-connectivity, 2. O(logk) approximation for k-node-connectivity 3. 2+ approximation for k-node-connectivity in Euclidian graph...

متن کامل

The Steiner Tree Reoptimization Problem with Sharpened Triangle Inequality

In this paper, we deal with several reoptimization variants of the Steiner tree problem in graphs obeying a sharpened β-triangle inequality. A reoptimization algorithm exploits the knowledge of an optimal solution to a problem instance for finding good solutions for a locally modified instance. We show that, in graphs satisfying a sharpened triangle inequality (and even in graphs where edge-cos...

متن کامل

On connected domination in unit ball graphs

Given a simple undirected graph, the minimum connected dominating set problem is to find a minimum cardinality subset of vertices D inducing a connected subgraph such that each vertex outside D has at least one neighbor in D. Approximations of minimum connected dominating sets are often used to represent a virtual routing backbone in wireless networks. This paper first proposes a constant-ratio...

متن کامل

Sufficient conditions for maximally edge-connected and super-edge-connected

Let $G$ be a connected graph with minimum degree $delta$ and edge-connectivity $lambda$. A graph ismaximally edge-connected if $lambda=delta$, and it is super-edge-connected if every minimum edge-cut istrivial; that is, if every minimum edge-cut consists of edges incident with a vertex of minimum degree.In this paper, we show that a connected graph or a connected triangle-free graph is maximall...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2003