On the 2-colored crossing number

O. Aichholzer, R. Fabila-Monroy, A. Fuchs, C. Hidalgo-Toscano, I. Parada, B. Vogtenhuber, and F. Zaragoza

Abstract:

Let $D$ be a straight-line drawing of a graph. The rectilinear 2-colored crossing number of $D$ is the minimum number of crossings between edges of the same color, taken over all possible 2-colorings of the edges of $D$. First, we show lower and upper bounds on the rectilinear 2-colored crossing number for the complete graph $K_n$. To obtain this result, we prove that asymptotic bounds can be derived from optimal and near-optimal instances with few vertices. We obtain such instances using a combination of heuristics and integer programming. Second, for any fixed drawing of $K_n$, we improve the bound on the ratio between its rectilinear 2-colored crossing number and its rectilinear crossing number.



Reference: O. Aichholzer, R. Fabila-Monroy, A. Fuchs, C. Hidalgo-Toscano, I. Parada, B. Vogtenhuber, and F. Zaragoza. On the 2-colored crossing number. In Graph Drawing and Network Visualization. GD 2019, volume 11904 of Lecture Notes in Computer Science (LNCS), pages 87-100, Prague, Czechia, 2019.

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