We study the problem how to draw a planar graph such that every vertex is incident to an angle greater than π. In general a straightline embedding cannot guarantee this property....
Abstract. We prove that for every graph H, there exists a polynomial-time algorithm deciding if a planar graph can be contracted to H. We introduce contractions and topological min...
A dual-eulerian graph is a plane graph which has an ordering defined on its edge set which forms simultaneously an Euler circuit in the graph and an euler circuit in the dual grap...