Abstract
A homomorphism from a graph G to a graph R is locally surjective if its restriction to the neighborhood of each vertex of G is surjective. Such a homomorphism is also called an R-role assignment of G. Role assignments have applications in distributed computing, social network theory, and topological graph theory. The Role Assignment problem has as input a pair of graphs (G,R) and asks whether G has an R-role assignment. This problem is NP-complete already on input pairs (G,R) where R is a path on three vertices. So far, the only known non-trivial tractable case consists of input pairs (G,R) where G is a tree. We present a polynomial time algorithm that solves Role Assignment on all input pairs (G,R) where G is a proper interval graph. Thus we identify the first graph class other than trees on which the problem is tractable. As a complementary result, we show that the problem is Graph Isomorphism-hard on chordal graphs, a superclass of proper interval graphs and trees.
Original language | English |
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Title of host publication | Combinatorial Algorithms - 21st International Workshop, IWOCA 2010, London, UK, July 26-28, 2010, Revised Selected Papers |
Editors | Costas S. Iliopoulos, William F. Smyth |
Publisher | Springer |
Pages | 167-180 |
Number of pages | 14 |
ISBN (Electronic) | 978-3-642-19222-7 |
ISBN (Print) | 978-3-642-19221-0 |
DOIs | |
Publication status | Published - 2010 |
Externally published | Yes |
Event | 21st International Workshop on Combinatorial Algorithms, IWOCA 2010 - London, United Kingdom Duration: 26 Jul 2010 → 28 Jul 2010 Conference number: 21 |
Publication series
Name | Lecture Notes in Computer Science |
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Publisher | Springer |
Volume | 6460 |
Conference
Conference | 21st International Workshop on Combinatorial Algorithms, IWOCA 2010 |
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Abbreviated title | IWOCA 2010 |
Country/Territory | United Kingdom |
City | London |
Period | 26/07/10 → 28/07/10 |