A Note on the Complexity of Computing the Smallest Four-Coloring of Planar Graphs

Andre Grosse; Joerg Rothe; Gerd Wechsung

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A Note on the Complexity of Computing the Smallest Four-Coloring of Planar Graphs

Andre Grosse·Joerg Rothe·Gerd Wechsung

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Abstract

We show that computing the lexicographically first four-coloring for planar graphs is P^{NP}-hard. This result optimally improves upon a result of Khuller and Vazirani who prove this problem to be NP-hard, and conclude that it is not self-reducible in the sense of Schnorr, assuming P \neq NP. We discuss this application to non-self-reducibility and provide a general related result.

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BibTeX RIS

Andre Grosse, Joerg Rothe, Gerd Wechsung. 2006-02-07. A Note on the Complexity of Computing the Smallest Four-Coloring of Planar Graphs. https://arxiv.org/abs/cs/0106045

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