Score: 0

Counting Triangulations of Fixed Cardinal Degrees

Published: October 6, 2025 | arXiv ID: 2510.04870v1

By: Erin Chambers , Tim Ophelders , Anna Schenfisch and more

Potential Business Impact:

Finds many ways to connect dots on a map.

Business Areas:
Navigation Navigation and Mapping

A fixed set of vertices in the plane may have multiple planar straight-line triangulations in which the degree of each vertex is the same. As such, the degree information does not completely determine the triangulation. We show that even if we know, for each vertex, the number of neighbors in each of the four cardinal directions, the triangulation is not completely determined. In fact, we show that counting such triangulations is #P-hard via a reduction from #3-regular bipartite planar vertex cover.

Page Count
21 pages

Category
Computer Science:
Computational Complexity