Efficient parallel algorithms for shortest paths in planar digraphs
نویسندگان
چکیده
منابع مشابه
Efficient Parallel Algorithms for Shortest Paths in Planar Graphs
Efficient parallel algorithms are presented, on the CREW PRAM model, for generating a succinct encoding of all pairs shortest path information in a directed planar graph G with real-valued edge costs but no negative cycles. We assume that a planar embedding of G is given, togetber with a set of q faces that cover all the vertices. Then our algorithm runs in O(log 2 n) time and employs O{nq + M(...
متن کاملFast Algorithms for Maintaining Shortest Paths in Outerplanar and Planar Digraphs
We present algorithms for maintaining shortest path information in dynamic outerplanar digraphs with sublogarithmic query time. By choosing appropriate parameters we achieve continuous trade-offs between the preprocessing, query, and update times. Our data structure is based on a recursive separator decomposition of the graph and it encodes the shortest paths between the members of a properly c...
متن کاملImplementing parallel shortest-paths algorithms
We have implemented a parallel version of the Bellman-Ford algorithm for the single-source shortest paths problem. Our software has been developed on the CM-5 using C with CMMD communication primitives. We have empirically compared the eeciency of our implementation with a sequential implementation of the Bellman-Ford-Moore algorithm developed by Cherkassky, Goldberg and Radzik. We have perform...
متن کاملEecient Algorithms for Shortest Path Queries in Planar Digraphs ?
This paper describes algorithms for answering shortest path queries in digraphs with small separators and, in particular, in planar digraphs. In this version of the problem, one has to preprocess the input graph so that, given an arbitrary pair of query vertices v and w, the shortest-path distance between v and w can be computed in a short time. The goal is to achieve balance between the prepro...
متن کاملOptimal Parallel Shortest Paths in Small Treewidth Digraphs
We consider the problem of preprocessing an n-vertex digraph with real edge weights so that subsequent queries for the shortest path or distance between any two vertices can be efficiently answered. We give parallel algorithms for the EREW PRAM model of computation that depend on the treewidth of the input graph. When the treewidth is a constant, our algorithms can answer distance queries in O(...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: BIT
سال: 1992
ISSN: 0006-3835,1572-9125
DOI: 10.1007/bf01994878