TY - GEN
T1 - Linear-time algorithms for hole-free rectilinear proportional contact graph representations
AU - Alam, Muhammad Jawaherul
AU - Biedl, Therese
AU - Felsner, Stefan
AU - Gerasch, Andreas
AU - Kaufmann, Michael
AU - Kobourov, Stephen G.
PY - 2011
Y1 - 2011
N2 - In a proportional contact representation of a planar graph, each vertex is represented by a simple polygon with area proportional to a given weight, and edges are represented by adjacencies between the corresponding pairs of polygons. In this paper we study proportional contact representations that use rectilinear polygons without wasted areas (white space). In this setting, the best known algorithm for proportional contact representation of a maximal planar graph uses 12-sided rectilinear polygons and takes O(nlogn) time. We describe a new algorithm that guarantees 10-sided rectilinear polygons and runs in O(n) time. We also describe a linear-time algorithm for proportional contact representation of planar 3-trees with 8-sided rectilinear polygons and show that this is optimal, as there exist planar 3-trees that require 8-sided polygons. Finally, we show that a maximal outer-planar graph admits a proportional contact representation using rectilinear polygons with 6 sides when the outer-boundary is a rectangle and with 4 sides otherwise.
AB - In a proportional contact representation of a planar graph, each vertex is represented by a simple polygon with area proportional to a given weight, and edges are represented by adjacencies between the corresponding pairs of polygons. In this paper we study proportional contact representations that use rectilinear polygons without wasted areas (white space). In this setting, the best known algorithm for proportional contact representation of a maximal planar graph uses 12-sided rectilinear polygons and takes O(nlogn) time. We describe a new algorithm that guarantees 10-sided rectilinear polygons and runs in O(n) time. We also describe a linear-time algorithm for proportional contact representation of planar 3-trees with 8-sided rectilinear polygons and show that this is optimal, as there exist planar 3-trees that require 8-sided polygons. Finally, we show that a maximal outer-planar graph admits a proportional contact representation using rectilinear polygons with 6 sides when the outer-boundary is a rectangle and with 4 sides otherwise.
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U2 - 10.1007/978-3-642-25591-5_30
DO - 10.1007/978-3-642-25591-5_30
M3 - Conference contribution
AN - SCOPUS:84055200211
SN - 9783642255908
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 281
EP - 291
BT - Algorithms and Computation - 22nd International Symposium, ISAAC 2011, Proceedings
T2 - 22nd International Symposium on Algorithms and Computation, ISAAC 2011
Y2 - 5 December 2011 through 8 December 2011
ER -