Oracles for Distances Avoiding a Failed Node or Link
We consider the problem of preprocessing an edge-weighted directed graph $G$ to answer queries that ask for the length and first hop of a shortest path from any given vertex $x$ to any given vertex $y$ avoiding any given vertex or edge. As a natural application, this problem models routing in networ...
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| Vydáno v: | SIAM journal on computing Ročník 37; číslo 5; s. 1299 - 1318 |
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| Hlavní autoři: | , , , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
Philadelphia, PA
Society for Industrial and Applied Mathematics
01.01.2008
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| Témata: | |
| ISSN: | 0097-5397, 1095-7111 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | We consider the problem of preprocessing an edge-weighted directed graph $G$ to answer queries that ask for the length and first hop of a shortest path from any given vertex $x$ to any given vertex $y$ avoiding any given vertex or edge. As a natural application, this problem models routing in networks subject to node or link failures. We describe a deterministic oracle with constant query time for this problem that uses $O(n^2\log n)$ space, where $n$ is the number of vertices in $G$. The construction time for our oracle is $O(mn^{2} + n^{3}\log n)$. However, if one is willing to settle for $\Theta (n^{2.5})$ space, we can improve the preprocessing time to $O(mn^{1.5}+n^{2.5}\log n)$ while maintaining the constant query time. Our algorithms can find the shortest path avoiding a failed node or link in time proportional to the length of the path. |
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| Bibliografie: | ObjectType-Article-1 SourceType-Scholarly Journals-1 content type line 14 |
| ISSN: | 0097-5397 1095-7111 |
| DOI: | 10.1137/S0097539705429847 |