We give a 2-approximation algorithm for the Maximum Agreement Forest problem on two rooted binary trees. This NP-hard problem has been studied extensively in the past two decades, since it can be used to compute the Subtree Prune-and-Regraft (SPR) distance between two phylogenetic trees. Our result improves on the very recent 2.5-approximation algorithm due to Shi, Feng, You and Wang (2015). Our algorithm is the first approximation algorithm for this problem that uses LP duality in its analysis.
@article{arxiv.1511.06000,
title = {A Duality Based 2-Approximation Algorithm for Maximum Agreement Forest},
author = {Frans Schalekamp and Anke van Zuylen and Suzanne van der Ster},
journal= {arXiv preprint arXiv:1511.06000},
year = {2016}
}