Upward drawings of triconnected digraphs
Upward drawings of triconnected digraphs
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DOI：
10.1007/bf01188716
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发表时间：
1994-12
期刊：
影响因子：
1.1
通讯作者：
P. Bertolazzi;G. Battista;G. Liotta;C. Mannino
中科院分区：
文献类型：
--
作者：
P. Bertolazzi;G. Battista;G. Liotta;C. Mannino
给出了一个判定三连通有向图是否有向上图的多项式时间算法。向上的旋翼是平面旋翼，使得所有边缘沿共同方向流动（例如，从底部到顶部）。这个问题出现在图的自动绘制和有序集领域，并且已经公开了几年。该算法基于一个新的组合特征，将问题转化为稀疏网络上的最大流问题，时间复杂度为O（n+r2），其中是有向图的顶点数，是有向图的源和汇数.如果有向图有一个向上的方向，算法允许我们很容易地构造一个。
A polynomial-time algorithm for testing if a triconnected directed graph has an upward drkwing is presented. An upward drkwing is a planar drkwing such that all the edges flow in a common direction (e.g., from bottom to top). The problem arises in the fields of automatic graph drkwing and ordered sets, and has been open for several years. The proposed algorithm is based on a new combinatorial characterization that maps the problem into a max-flow problem on a sparse network; the time complexity isO(n+r2), wherenis the number of vertices andris the number of sources and sinks of the directed graph. If the directed graph has an upward drkwing, the algorithm allows us to construct one easily.