### Abstract

A Stick graph is an intersection graph of axis-aligned segments such that the left end-points of the horizontal segments and the bottom end-points of the vertical segments lie on a “ground line,” a line with slope −1. It is an open question to decide in polynomial time whether a given bipartite graph G with bipartition A∪B has a Stick representation where the vertices in A and B correspond to horizontal and vertical segments, respectively. We prove that G has a Stick representation if and only if there are orderings of A and B such that G's bipartite adjacency matrix with rows A and columns B excludes three small ‘forbidden’ submatrices. This is similar to characterizations for other classes of bipartite intersection graphs. We present an algorithm to test whether given orderings of A and B permit a Stick representation respecting those orderings, and to find such a representation if it exists. The algorithm runs in time linear in the size of the adjacency matrix. For the case when only the ordering of A is given, or neither ordering is given, we present some partial results about graphs that are, or are not, Stick representable.

Original language | English (US) |
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Journal | Theoretical Computer Science |

DOIs | |

State | Accepted/In press - Jan 1 2019 |

### Fingerprint

### Keywords

- Bipartite Graphs
- Graph Drawing
- Intersection Graphs
- Stick Graphs

### ASJC Scopus subject areas

- Theoretical Computer Science
- Computer Science(all)

### Cite this

*Theoretical Computer Science*. https://doi.org/10.1016/j.tcs.2019.08.018

**Recognition and drawing of stick graphs.** / De Luca, Felice; Hossain, Md Iqbal; Kobourov, Stephen G; Lubiw, Anna; Mondal, Debajyoti.

Research output: Contribution to journal › Article

*Theoretical Computer Science*. https://doi.org/10.1016/j.tcs.2019.08.018

}

TY - JOUR

T1 - Recognition and drawing of stick graphs

AU - De Luca, Felice

AU - Hossain, Md Iqbal

AU - Kobourov, Stephen G

AU - Lubiw, Anna

AU - Mondal, Debajyoti

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A Stick graph is an intersection graph of axis-aligned segments such that the left end-points of the horizontal segments and the bottom end-points of the vertical segments lie on a “ground line,” a line with slope −1. It is an open question to decide in polynomial time whether a given bipartite graph G with bipartition A∪B has a Stick representation where the vertices in A and B correspond to horizontal and vertical segments, respectively. We prove that G has a Stick representation if and only if there are orderings of A and B such that G's bipartite adjacency matrix with rows A and columns B excludes three small ‘forbidden’ submatrices. This is similar to characterizations for other classes of bipartite intersection graphs. We present an algorithm to test whether given orderings of A and B permit a Stick representation respecting those orderings, and to find such a representation if it exists. The algorithm runs in time linear in the size of the adjacency matrix. For the case when only the ordering of A is given, or neither ordering is given, we present some partial results about graphs that are, or are not, Stick representable.

AB - A Stick graph is an intersection graph of axis-aligned segments such that the left end-points of the horizontal segments and the bottom end-points of the vertical segments lie on a “ground line,” a line with slope −1. It is an open question to decide in polynomial time whether a given bipartite graph G with bipartition A∪B has a Stick representation where the vertices in A and B correspond to horizontal and vertical segments, respectively. We prove that G has a Stick representation if and only if there are orderings of A and B such that G's bipartite adjacency matrix with rows A and columns B excludes three small ‘forbidden’ submatrices. This is similar to characterizations for other classes of bipartite intersection graphs. We present an algorithm to test whether given orderings of A and B permit a Stick representation respecting those orderings, and to find such a representation if it exists. The algorithm runs in time linear in the size of the adjacency matrix. For the case when only the ordering of A is given, or neither ordering is given, we present some partial results about graphs that are, or are not, Stick representable.

KW - Bipartite Graphs

KW - Graph Drawing

KW - Intersection Graphs

KW - Stick Graphs

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UR - http://www.scopus.com/inward/citedby.url?scp=85071653445&partnerID=8YFLogxK

U2 - 10.1016/j.tcs.2019.08.018

DO - 10.1016/j.tcs.2019.08.018

M3 - Article

AN - SCOPUS:85071653445

JO - Theoretical Computer Science

JF - Theoretical Computer Science

SN - 0304-3975

ER -