Building Blocks of Upward Planar Digraphs
نویسندگان
چکیده
The upward planarity testing problem consists of testing if a digraph admits a drawing Γ such that all edges in Γ are monotonically increasing in the vertical direction and no edges in Γ cross. In this paper we reduce the problem of testing a digraph for upward planarity to the problem of testing if its blocks admit upward planar drawings with certain properties. We also show how to test if a block of a digraph admits an upward planar drawing with the aforementioned properties. Article Type Communicated by Submitted Revised Regular Paper G. Di Battista May 2005 August 2006 Healy and Lynch, Blocks and Upward Planarity , JGAA, 11(1) 3–44 (2007) 4
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