,
Asif Khan
,
Pranabendu Misra
Creative Commons Attribution 4.0 International license
We study the problem of connectivity augmentation of a planar graph, while preserving planarity. This problem is motivated by many real-world settings such as road-networks, power-networks etc. In these settings, it is crucial to preserve the original planar embedding after augmentation. In 2009, Gutwenger and Mutzel gave a constructive algorithm showing that a connected planar graph with a fixed embedding (a plane graph) can be optimally augmented to a biconnected graph without crossings while preserving the embedding. We further this line of research, by giving an algorithm that computes a minimum set of edges that makes a connected plane graph 2-edge-connected in O(|V|(1+α(|V|))) time and linear space, where α is the inverse Ackermann function. We also study the 3-vertex-connectivity augmentation of biconnected outerplanar plane graphs. We present the first polynomial-time algorithm that augments such graphs to 3-connectivity with the minimum number of edges in O(|V|(1+α(|V|))) time and linear space while preserving the embedding, i.e. the augmented graph has a planar embedding that extends the given embedding.
@InProceedings{dehaleesan_et_al:LIPIcs.MFCS.2026.23,
author = {Dehaleesan, Krishnan and Khan, Asif and Misra, Pranabendu},
title = {{Connectivity Augmentation of Plane Graphs}},
booktitle = {51st International Symposium on Mathematical Foundations of Computer Science (MFCS 2026)},
pages = {23:1--23:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-442-0},
ISSN = {1868-8969},
year = {2026},
volume = {386},
editor = {Kouck\'{y}, Michal and Petrișan, Daniela},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2026.23},
URN = {urn:nbn:de:0030-drops-274044},
doi = {10.4230/LIPIcs.MFCS.2026.23},
annote = {Keywords: Connectivity augmentation, Plane graphs, Bridgetree, BC-tree, Balanced graph}
}