Shortest Path Queries in Digraphs of Small Treewidth

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 algorithms that depend on the treewidth of the input graph. When the treewidth is a constant, our algorithms can answer distance queries in O(α(n)) time after O(n) preprocessing. This improves upon previously known results for the same problem. We also give a dynamic algorithm which, after a change in an edge weight, updates

• Type: Conference
• Year: 1995
• Where: ICALP
• Authors: Shiva Chaudhuri, Christos D. Zaroliagis
• Keywords: Algorithm, Edge Weight, ICALP 1995, Programming Languages, Real Edge Weights