ICS Theory Group

February 26, Winter Quarter 2010: Theory Seminar

1:00pm in 1423 Bren Hall

Solving the Replacement Paths Problem for Planar Directed Graphs in O(n log n) Time

Lowell Trott, UC Irvine

Presenting a paper by Christian Wulff-Nilsen

Abstract: In a graph G with non-negative edge lengths, let P be a shortest path from a vertex s to a vertex t. We consider the problem of computing, for each edge e on P , the length of a shortest path in G from s to t that avoids e. This is known as the replacement paths problem. We give a linear- space algorithm with O(n log n) running time for n-vertex planar directed graphs. The previous best time bound was O(n log2 n).