Abstract
Two discrete optimization problems arising in VLSI are to reduce the area of a programmable logic array (PLA) and to separate graphs uniformly. We show that a commonly used area reduction technique called blockfolding is equivalent to separating graphs by vertex deletion. The later problem is shown to be NP-complete even for 3-regular-graphs.
Zusammenfassung
Zwei diskrete Optimierungsprobleme beim VLSI-Design sind die Fläche eines programmierbaren logischen Arrays (PLA) zu reduzieren und einen Graphen in möglichst gleich große Teilgraphen zu zerlegen. Wir zeigen, daß eine in der Praxis oft benutzte Flächenreduktionstechnik, das Blockfolding, äquivalent ist zu dem Problem, Graphen durch Wegnahme von Knoten zu zerlegen. Es wird gezeigt, daß dieses Problem schon für 3-reguläre GraphenNP-schwer ist.
Similar content being viewed by others
References
[BCLS87] Bui, T. N., Chaudhuri, S., Leighton, F. T., Sipser, M.: Graph bisection algorithms with good average case behavior. Combinatorica7, 171–191 (1987).
[Bo87] Bodländer, H. L.: Dynamic programming on graphs with bounded tree width. Report RUU-CS-87-22 University of Utrecht (1987).
[EL84] Egan, J. R., Liu, C. L.: Bipartite folding and partitioning of a PLA, IEEE Trans. CAD3, 191–199 (1984).
[GJ] Garey, M. R., Johnson, D. S.: Computers and intractibility. New York, 1979.
[GJS76] Garey, M. R., Johnson, P. S., Stockmeyer, L.: Simplified NP-complete graph problems. Theoretical Computer Science1, 237–267 (1976).
[Jo87] Johnson, David S.: The NP-completeness column: an ongoing guide. J. Algorithms8, 438–448 (1987).
[LT79] Lipton, R. J., Tarjan R. E.: A separator theorem for planar graphs. SIAM J. Appl. Mathematics36, 177–189 (1979).
[Mi84] Miller, G.: Finding small simple cycle separators for 2-connected planar graphs, Proc. 16th, Anm. ACM Sympos. on Theory of Computing 376–382 (1984).
[Mö90] Möhring, R. H.: Graph problems related to gate matrix layout and PLA folding, In: Tinhofer G. et. al. (eds.) Computing Supplementum 7, Computational graph theory, Springer (1990), 17–52.
[UL83] Ullman, J. D.: Computational aspects of VLSI. Rockville, USA: Computer Science Press, (1983).
[WW91] Wagner, D., Wagner, F.: Between min cut and graph bisection, Report B-91-1, Freie Universität Berlin (1991).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Müller, R., Wagner, D. α-Vertex separator is NP-hard even for 3-regular graphs. Computing 46, 343–353 (1991). https://doi.org/10.1007/BF02257778
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02257778