Autor: |
Matthias F. Stallmann, Xiao Yu Li |
Rok vydání: |
2002 |
Předmět: |
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Zdroj: |
Information Processing Letters. 82:293-298 |
ISSN: |
0020-0190 |
DOI: |
10.1016/s0020-0190(01)00297-6 |
Popis: |
The barycenter heuristic is often used to solve the NP-hard two-layer edge crossing minimization problem. It is well known that the barycenter heuristic can give solutions as bad as Ω( n ) times the optimum, where n is the number of nodes in the graph. However, the example used in the proof has many isolated nodes. Makinen [EATCS Bull. 70 (2000) 156–158] conjectured that a better performance ratio is possible if isolated nodes are not present. We show that the performance ratio for the barycenter heuristic is still Ω( n ) even for connected bipartite graphs. We also prove a tight constant ratio for the barycenter heuristic on bounded-degree graphs. The performance ratio is d−1, where d is the maximum degree of a node in the layer that can be permuted. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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