Reconstructing graphs from connected triples

With Paul Bastide*, Linda Cook, Carla Groenland, Marc van Kreveld, Isja Mannens*, and Jordi L. Vermeulen*

Submitted to the 49th International Workshop on Graph-Theoretic Concepts in Computer Science.

We introduce a new model of indeterminacy in graphs: instead of specifying all the edges of the graph, the input contains all triples of vertices that form a connected subgraph. In general, different (labelled) graphs may have the same set of connected triples, making unique reconstruction of the original graph from the triples impossible. We identify some families of graphs (including triangle-free graphs) for which all graphs have a different set of connected triples. We also give algorithms that reconstruct a graph from a set of triples, and for testing if this reconstruction is unique. Finally, we study a possible extension of the model in which the subsets of size k that induce a connected graph are given for larger (fixed) values of k.

Publications - Jeff Erickson ( 30 Mar 2023