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A simple and linear time randomized algorithm for computing sparse spanners in weighted graphs
Surender Baswana,Sandeep Sen +1 more
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The size of the t-spanner computed essentially matches the worst case lower bound implied by a 43-year old girth lower bound conjecture made independently by Erdos, Bollobas, and Bondy & Simonovits.Abstract:
Let G = (V,E) be an undirected weighted graph on |V | = n vertices and |E| = m edges. A t-spanner of the graph G, for any t ≥ 1, is a subgraph (V,ES), ES ⊆ E, such that the distance between any pair of vertices in the subgraph is at most t times the distance between them in the graph G. Computing a t-spanner of minimum size (number of edges) has been a widely studied and well-motivated problem in computer science. In this paper we present the first linear time randomized algorithm that computes a t-spanner of a given weighted graph. Moreover, the size of the t-spanner computed essentially matches the worst case lower bound implied by a 43-year old girth lower bound conjecture made independently by Erdos, Bollobas, and Bondy & Simonovits.
Our algorithm uses a novel clustering approach that avoids any distance computation altogether. This feature is somewhat surprising since all the previously existing algorithms employ computation of some sort of local or global distance information, which involves growing either breadth first search trees up to t(t)-levels or full shortest path trees on a large fraction of vertices. The truly local approach of our algorithm also leads to equally simple and efficient algorithms for computing spanners in other important computational environments like distributed, parallel, and external memory. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Preliminary version of this work appeared in the 30th International Colloquium on Automata, Languages and Programming, pages 384–396, 2003.read more
Citations
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Proceedings ArticleDOI
Graph sketches: sparsification, spanners, and subgraphs
TL;DR: This work investigates graph sketching where the graphs of interest encode the relationships between these entities and considers properties of graphs including the size of the cuts, the distances between nodes, and the prevalence of dense sub-graphs.
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On Dynamic Shortest Paths Problems
Liam Roditty,Uri Zwick +1 more
TL;DR: Reductions that show that the incremental and decremental single-source shortest-paths problems, for weighted directed or undirected graphs, are, in a strong sense, at least as hard as the static all-pairs shortest- Paths problem.
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Distributed Approximation Algorithms for Weighted Shortest Paths
TL;DR: In this paper, the authors presented an algorithm for computing both single-source shortest paths (sssp) and all-pairs shortest paths in the weighted case with a running time of O(1+o(1)).
Proceedings ArticleDOI
Distributed approximation algorithms for weighted shortest paths
TL;DR: The time complexity of approximating weighted (undirected) shortest paths on distributed networks with a O (log n) bandwidth restriction on edges is studied to find a sublinear-time algorithm with almost optimal solution.
Journal ArticleDOI
Sparse roadmap spanners for asymptotically near-optimal motion planning
Andrew Dobson,Kostas E. Bekris +1 more
TL;DR: Simulations for rigid-body motion planning show that algorithms for constructing sparse roadmap spanners indeed provide small data structures and result in faster query resolution, and suggests that finite-size data structures with asymptotic near-optimality in continuous spaces may indeed exist.
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TL;DR: This paper gives a simple algorithm for constructing sparse spanners for arbitrary weighted graphs and applies this algorithm to obtain specific results for planar graphs and Euclidean graphs.