Aug 30, 2022 · We show how to recognize directional interval graphs, and how to compute their chromatic number efficiently.
Jan 19, 2023 · We show how to recognize directional interval graphs, and how to compute their chromatic number efficiently.
directional interval graphs, which is based on PQ-trees. □ For the more general case of mixed interval graphs, coloring is NP-hard. (Remark: NP-hardness ...
Framework for layered graph drawing by Sugiyama, Tagawa, and Toda (1981). 1. cycle elimination. 2. layer assignment. 3. crossing minimization. 4. node placement.
Jan 19, 2023 · Coloring such graphs has applications in routing edges in layered orthogonal graph drawing according to the Sugiyama framework; the colors ...
A mixed interval graph is an interval graph that has, for every pair of intersecting intervals, either an arc (directed arbitrarily) or an (undirected) edge. We ...
A mixed graph has a set of vertices, a set of undirected egdes, and a set of directed arcs. A proper coloring of a mixed graph $G$ is a function $c$ that ...
A mixed interval graph is an interval graph that has, for every pair of intersecting intervals, either an arc (directed arbitrarily) or an (undirected) edge. We ...
A directional interval graph is a mixed graph whose vertices correspond to intervals on the real line. Such a graph has an edge between every two intervals ...