Algorithms for Local Forest Similarity

An ordered labeled tree is a rooted tree, where the left-to-right order among siblings is significant and each node associates a label. A forest is a sequence of ordered labeled trees. Suppose F is a forest. A substructure is a connected subgraph of F. Define a subforest as a sequence of substructures of F such that their roots are siblings. The local forest similarity problem for forests F and G is to find two most similar subforests of F and G. We answer an open problem in Paper [3], and provide efficient algorithms on it. Comparing with previous results, our algorithms achieve better performance.