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arXiv · 1708.01765

Grid Obstacle Representation of Graphs

Arijit Bishnu·Arijit Ghosh·Rogers Mathew·Gopinath Mishra·Subhabrata Paul
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Abstract

The grid obstacle representation, or alternately, $\ell_1$-obstacle representation of a graph $G=(V,E)$ is an injective function $f:V \rightarrow \mathbb{Z}^2$ and a set of point obstacles $\mathcal{O}$ on the grid points of $\mathbb{Z}^2$ (where no vertex of $V$ has been mapped) such that $uv$ is an edge in $G$ if and only if there exists a Manhattan path between $f(u)$ and $f(v)$ in $\mathbb{Z}^2$ avoiding the obstacles of $\mathcal{O}$ and points in $f(V)$. This work shows that planar graphs admit such a representation while there exist some non-planar graphs that do not admit such a representation. Moreover, we show that every graph admits a grid obstacle representation in $\mathbb{Z}^3$. We also show NP-hardness result for the point set embeddability of an $\ell_1$-obstacle representation.

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Arijit Bishnu, Arijit Ghosh, Rogers Mathew, Gopinath Mishra, Subhabrata Paul. 2017-08-05. Grid Obstacle Representation of Graphs. https://arxiv.org/abs/1708.01765

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