,
Stephen Kobourov
,
Jacob Miller
,
Johannes Zink
Creative Commons Attribution 4.0 International license
A strengthened version of Harborth’s well-known conjecture - known as Kleber’s conjecture - states that every planar graph admits a planar straight-line drawing where every edge has integer length and each vertex is restricted to the integer grid. Positive results for Kleber’s conjecture are known for planar 3-regular graphs, for planar graphs that have maximum degree 4, and for planar 3-trees. However, all but one of the existing results are existential and do not provide bounds on the required grid size. We provide polynomial-time algorithms for computing crossing-free straight-line drawings of trees and cactus graphs with integer edge lengths and integer vertex position on polynomial-size integer grids. We also give an historic overview of planar straight-line graph drawing results.
@InProceedings{forster_et_al:LIPIcs.GD.2025.48,
author = {F\"{o}rster, Henry and Kobourov, Stephen and Miller, Jacob and Zink, Johannes},
title = {{Drawing Trees and Cacti with Integer Edge Lengths on a Polynomial-Size Grid}},
booktitle = {33rd International Symposium on Graph Drawing and Network Visualization (GD 2025)},
pages = {48:1--48:4},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-403-1},
ISSN = {1868-8969},
year = {2025},
volume = {357},
editor = {Dujmovi\'{c}, Vida and Montecchiani, Fabrizio},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.GD.2025.48},
URN = {urn:nbn:de:0030-drops-250349},
doi = {10.4230/LIPIcs.GD.2025.48},
annote = {Keywords: Harborth’s conjecture, tree drawings, cactus drawings, grid drawings}
}