Reconstruction of Trees from Jumbled and Weighted Subtrees

Let T be an edge-labeled graph, where the labels are from a finite alphabet Σ. For a subtree U of T , the Parikh vector of U is a vector of length |Σ| which specifies the multiplicity of each label in U . We ask when T can be reconstructed from the multiset of Parikh vectors of all of its subtrees, or all of its paths, or all of its maximal paths. We consider the analogous problems for weighted trees. We show how several well-known reconstruction problems on labeled strings, weighted strings and point sets on a line can be included in this framework. We present reconstruction algorithms and non-reconstructibility results, and extend the polynomial method, previously applied to jumbled strings [Acharya et al, SIAM J on Discr. Math, 2015] and weighted strings [Bansal et al, CPM 2004], to deal with general trees and special tree classes. 1998 ACM Subject Classification F.2.2 [Nonnumerical Algorithms and Problems] Computations on discrete structures, G.2.2 [Graph Theory] Graph labeling, Trees