A linear tree edit distance algorithm for similar ordered trees

Abstract

We describe a linear algorithm for comparing two similar ordered rooted trees with node labels. The method for comparing trees is the usual tree edit distance. We show that an optimal mapping which uses at most k insertions or deletions can then be constructed in O(nk3) where n is the size of the trees. The approach is inspired by the Zhang-Shasha algorithm for tree edit distance in combination with an adequate pruning of the search space. © Springer-Verlag Berlin Heidelberg 2005.