# Mincut Sensitivity Data Structures for the Insertion of an Edge

S. Baswana, S. Gupta, T. Knollmann, in: F. Grandoni, G. Herman, P. Sanders (Eds.), 28th Annual European Symposium on Algorithms (ESA 2020), Schloss Dagstuhl -- Leibniz-Zentrum für Informatik, Dagstuhl, Germany, 2020, pp. 12:1-12:14.

Conference Paper | English
Author
Baswana, Surender; Gupta, Shiv; Knollmann, TillLibreCat
Editor
Grandoni, Fabrizio; Herman, Grzegorz; Sanders, Peter
Abstract
Let G = (V,E) be an undirected graph on n vertices with non-negative capacities on its edges. The mincut sensitivity problem for the insertion of an edge is defined as follows. Build a compact data structure for G and a given set S ⊆ V of vertices that, on receiving any edge (x,y) ∈ S×S of positive capacity as query input, can efficiently report the set of all pairs from S× S whose mincut value increases upon insertion of the edge (x,y) to G. The only result that exists for this problem is for a single pair of vertices (Picard and Queyranne, Mathematical Programming Study, 13 (1980), 8-16). We present the following results for the single source and the all-pairs versions of this problem. 1) Single source: Given any designated source vertex s, there exists a data structure of size 𝒪(|S|) that can output all those vertices from S whose mincut value to s increases upon insertion of any given edge. The time taken by the data structure to answer any query is 𝒪(|S|). 2) All-pairs: There exists an 𝒪(|S|²) size data structure that can output all those pairs of vertices from S× S whose mincut value gets increased upon insertion of any given edge. The time taken by the data structure to answer any query is 𝒪(k), where k is the number of pairs of vertices whose mincut increases. For both these versions, we also address the problem of reporting the values of the mincuts upon insertion of any given edge. To derive our results, we use interesting insights into the nearest and the farthest mincuts for a pair of vertices. In addition, a crucial result, that we establish and use in our data structures, is that there exists a directed acyclic graph of 𝒪(n) size that compactly stores the farthest mincuts from all vertices of V to a designated vertex s in the graph. We believe that this result is of independent interest, especially, because it also complements a previously existing result by Hariharan et al. (STOC 2007) that the nearest mincuts from all vertices of V to s is a laminar family, and hence, can be stored compactly in a tree of 𝒪(n) size.
Keywords
Publishing Year
Proceedings Title
28th Annual European Symposium on Algorithms (ESA 2020)
forms.conference.field.series_title_volume.label
Leibniz International Proceedings in Informatics (LIPIcs)
Volume
173
Page
12:1-12:14
ISSN
LibreCat-ID

### Cite this

Baswana S, Gupta S, Knollmann T. Mincut Sensitivity Data Structures for the Insertion of an Edge. In: Grandoni F, Herman G, Sanders P, eds. 28th Annual European Symposium on Algorithms (ESA 2020). Vol 173. Leibniz International Proceedings in Informatics (LIPIcs). Dagstuhl, Germany: Schloss Dagstuhl -- Leibniz-Zentrum für Informatik; 2020:12:1-12:14. doi:10.4230/LIPIcs.ESA.2020.12
Baswana, S., Gupta, S., & Knollmann, T. (2020). Mincut Sensitivity Data Structures for the Insertion of an Edge. In F. Grandoni, G. Herman, & P. Sanders (Eds.), 28th Annual European Symposium on Algorithms (ESA 2020) (Vol. 173, pp. 12:1-12:14). Dagstuhl, Germany: Schloss Dagstuhl -- Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.ESA.2020.12
@inproceedings{Baswana_Gupta_Knollmann_2020, place={Dagstuhl, Germany}, series={Leibniz International Proceedings in Informatics (LIPIcs)}, title={Mincut Sensitivity Data Structures for the Insertion of an Edge}, volume={173}, DOI={10.4230/LIPIcs.ESA.2020.12}, booktitle={28th Annual European Symposium on Algorithms (ESA 2020)}, publisher={Schloss Dagstuhl -- Leibniz-Zentrum für Informatik}, author={Baswana, Surender and Gupta, Shiv and Knollmann, Till}, editor={Grandoni, Fabrizio and Herman, Grzegorz and Sanders, PeterEditors}, year={2020}, pages={12:1-12:14}, collection={Leibniz International Proceedings in Informatics (LIPIcs)} }
Baswana, Surender, Shiv Gupta, and Till Knollmann. “Mincut Sensitivity Data Structures for the Insertion of an Edge.” In 28th Annual European Symposium on Algorithms (ESA 2020), edited by Fabrizio Grandoni, Grzegorz Herman, and Peter Sanders, 173:12:1-12:14. Leibniz International Proceedings in Informatics (LIPIcs). Dagstuhl, Germany: Schloss Dagstuhl -- Leibniz-Zentrum für Informatik, 2020. https://doi.org/10.4230/LIPIcs.ESA.2020.12.
S. Baswana, S. Gupta, and T. Knollmann, “Mincut Sensitivity Data Structures for the Insertion of an Edge,” in 28th Annual European Symposium on Algorithms (ESA 2020), 2020, vol. 173, pp. 12:1-12:14.
Baswana, Surender, et al. “Mincut Sensitivity Data Structures for the Insertion of an Edge.” 28th Annual European Symposium on Algorithms (ESA 2020), edited by Fabrizio Grandoni et al., vol. 173, Schloss Dagstuhl -- Leibniz-Zentrum für Informatik, 2020, pp. 12:1-12:14, doi:10.4230/LIPIcs.ESA.2020.12.

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