Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-16T16:15:41.137Z Has data issue: false hasContentIssue false

Counting Plane Graphs: Cross-Graph Charging Schemes

Published online by Cambridge University Press:  25 July 2013

MICHA SHARIR
Affiliation:
School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel and Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA (e-mail: [email protected])
ADAM SHEFFER
Affiliation:
School of Computer Science, Tel Aviv University, Tel Aviv 69978, Israel (e-mail: [email protected])

Abstract

We study cross-graph charging schemes for graphs drawn in the plane. These are charging schemes where charge is moved across vertices of different graphs. Such methods have recently been used to obtain various properties of triangulations that are embedded in a fixed set of points in the plane. We generalize this method to obtain results for various other types of graphs that are embedded in the plane. Specifically, we obtain a new bound of O*(187.53N) (where the O*(⋅) notation hides polynomial factors) for the maximum number of crossing-free straight-edge graphs that can be embedded in any specific set of N points in the plane (improving upon the previous best upper bound 207.85N in Hoffmann, Schulz, Sharir, Sheffer, Tóth and Welzl [14]). We also derive upper bounds for numbers of several other types of plane graphs (such as connected and bi-connected plane graphs), and obtain various bounds on the expected vertex-degrees in graphs that are uniformly chosen from the set of all crossing-free straight-edge graphs that can be embedded in a specific point set.

We then apply the cross-graph charging-scheme method to graphs that allow certain types of crossings. Specifically, we consider graphs with no set of k pairwise crossing edges (more commonly known as k-quasi-planar graphs). For k=3 and k=4, we prove that, for any set S of N points in the plane, the number of graphs that have a straight-edge k-quasi-planar embedding over S is only exponential in N.

Type
Paper
Copyright
Copyright © Cambridge University Press 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Ackerman, E. (2009) On the maximum number of edges in topological graphs with no four pairwise crossing edges. Discrete Comput. Geom. 41 365375.CrossRefGoogle Scholar
[2]Ackerman, E. and Tardos, G. (2007) On the maximum number of edges in quasi-planar graphs. J. Combin. Theory Ser. A 114 563571.Google Scholar
[3]Aichholzer, O., Hackl, T., Huemer, C., Hurtado, F., Krasser, H. and Vogtenhuber, B. (2007) On the number of plane geometric graphs. Graphs Combin. 23 6784.Google Scholar
[4]Ajtai, M., Chvátal, V., Newborn, M. M. and Szemerédi, E. (1982) Crossing-free subgraphs. Ann. Discrete Math. 12 912.Google Scholar
[5]Appel, K. and Haken, W. (1977) Every planar map is four colorable I: Discharging. Illinois J. Math. 21 429490.Google Scholar
[6]Buchin, K. and Schulz, A. (2010) On the number of spanning trees a planar graph can have. In Proc. 18th Annual European Symposium on Algorithms, Vol. 6346 of Lecture Notes in Computer Science, Springer, pp. 110121.Google Scholar
[7]Buchin, K., Knauer, C., Kriegel, K., Schulz, A. and Seidel, R. (2007) On the number of cycles in planar graphs. In Proc. 17th Computing and Combinatorics Conference, Vol. 4598 of Lecture Notes in Computer Science, Springer, pp. 97107.Google Scholar
[8]Denny, M. O. and Sohler, C. A. (1997) Encoding a triangulation as a permutation of its point set. In Proc. 9th Canadian Conference on Computational Geometry, Queen's university, Kingston, Ontario, pp. 3943.Google Scholar
[9]Dumitrescu, A., Schulz, A., Sheffer, A. and Tóth, C. D. (2011) Bounds on the maximum multiplicity of some common geometric graphs. In Proc. 28th Symposium on Theoretical Aspects of Computer Science, pp. 637–648. http://www.stacs-conf.org/Google Scholar
[10]Euler, L. (1761) Enumeratio modorum, quibus figurae planae rectilineae per diagonales diuiduntur in triangula. Novi Commentarii Academiae Scientiarum Petropolitanae 7 1315.Google Scholar
[11]Flajolet, P. and Noy, M. (1999) Analytic combinatorics of non-crossing configurations. Discrete Math. 204 203229.Google Scholar
[12]García, A., Noy, M. and Tejel, J. (2000) Lower bounds on the number of crossing-free subgraphs of KN. Comput. Geom. Theory Appl. 16 211221.Google Scholar
[13]Heesch, H. (1969) Untersuchungen zum Vierfarbenproblem. Hochschulscripten 810/a/b, Bibliographisches Institut, Mannheim.Google Scholar
[14]Hoffmann, M., Schulz, A., Sharir, M., Sheffer, A., Tóth, C. D. and Welzl, E.Counting plane graphs: Flippability and its applications. In Thirty Essays on Geometric Graph Theory (Pach, J., ed.), Springer, pp. 303325.Google Scholar
[15]Lamé, G. (1838) Extrait d'une lettre de M. Lamé à M. Liouville sur cette question: Un polygone convexe étant donné, de combien de manières peut-on le partager en triangles au moyen de diagonales? Journal de Mathématiques Pures et Appliquées 3 505507.Google Scholar
[16]Pach, J. (2004) Geometric graph theory. In Handbook of Discrete and Computational Geometry (Goodman, J. E. and O'Rourke, J., eds), second edition, CRC Press, pp. 219238.Google Scholar
[17]Radoičić, R. and Tóth, G. (2008) The discharging method in combinatorial geometry and the Pach–Sharir conjecture. In Surveys on Discrete and Computational Geometry (Goodman, J. E., Pach, J. and Pollack, J., eds), AMS, pp. 319342.Google Scholar
[18]Razen, A. and Welzl, E. (2011) Counting crossing-free geometric graphs with exponential speed-up. In Rainbow of Computer Science, Vol. 6570 of Lecture Notes in Computer Science, Springer, pp. 3646.Google Scholar
[19]Razen, A., Snoeyink, J. and Welzl, E. (2008) Number of crossing-free geometric graphs vs. triangulations. Electron. Notes Discrete Math. 31 195200.Google Scholar
[20]RibóMor, A. Mor, A. (2005) Realizations and counting problems for planar structures: Trees and linkages, polytopes and polyominos. PhD thesis, Freie Universität Berlin.Google Scholar
[21]Rote, G. (2005) The number of spanning trees in a planar graph. Oberwolfach Reports 2 969973.Google Scholar
[22]Santos, F. and Seidel, R. (2003) A better upper bound on the number of triangulations of a planar point set. J. Combin. Theory Ser. A 102 186193.Google Scholar
[23]Sharir, M. and Sheffer, A. (2011) Counting triangulations of planar point sets. Electron. J. Combin. 18 #P70.Google Scholar
[24]Sharir, M. and Welzl, E. (2006) Random triangulations of planar point sets. In Proc. 22nd ACM Symposium on Computational Geometry, ACM, New York, NY, USA, pp. 273281.Google Scholar
[25]Sharir, M., Sheffer, A. and Welzl, E. (2011) On degrees in random triangulations of point sets. J. Combin. Theory Ser. A 118 19791999.Google Scholar
[26]Valtr, P. (1997) Graph drawings with no k pairwise crossing edges. In Proc. 5th International Symposium on Graph Drawing, Springer, Berlin, pp. 205218.CrossRefGoogle Scholar