Title
Counting Euler Tours in Undirected Bounded Treewidth Graphs
Abstract
We show that counting Euler tours in undirected bounded tree-width graphs is tractable even in parallel - by proving a GapL upper bound. This is in stark contrast to #P-completeness of the same problem in general graphs. main technical contribution is to show how (an instance of) dynamic programming on bounded clique-width graphs can be performed efficiently in parallel. Thus we show that the sequential result of Espelage, Gurski and Wanke for efficiently computing Hamiltonian paths in bounded clique-width graphs can be adapted in the parallel setting to count the number of Hamiltonian paths which in turn is a tool for counting the number of Euler tours in bounded tree-width graphs. Our technique also yields parallel algorithms for counting longest paths and bipartite perfect matchings in bounded-clique width graphs.While establishing that counting Euler tours in bounded tree-width graphs can be computed by non-uniform monotone arithmetic circuits of polynomial degree (which characterize #SAC^1) is relatively easy, establishing a uniform #SAC^1 bound needs a careful use of polynomial interpolation.
Year
DOI
Venue
2015
10.4230/LIPIcs.FSTTCS.2015.246
foundations of software technology and theoretical computer science
DocType
Volume
Citations 
Journal
abs/1510.04035
3
PageRank 
References 
Authors
0.43
19
3
Name
Order
Citations
PageRank
Nikhil Balaji194.24
Samir Datta220019.82
Venkatesh Ganesan330.43