Greedy Consensus Tree and Maximum Greedy Consensus Tree Problems

  • Wing-Kin SungEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11355)


Consensus tree is a phylogenetic tree that summarizes the branching information of a set of conflicting phylogenetic trees. Computing consensus tree is a major step in phylogenetic tree reconstruction. It also finds application in predicting a species tree from a set of gene trees. Here, we focus our study on one of the most frequently used consensus tree problem, called greedy consensus tree problem. Given k phylogenetic trees leaf-labeled by n taxa, previous best known algorithm for constructing a greedy consensus tree of these k trees runs in \(O(k n^{1.5} \log n)\) time. Here, we describe an \(O(k^2 n)\)-time solution. Our method is the fastest when \(k = O(\sqrt{n} \log n)\).

Existing greedy consensus tree methods may not report the most resolved greedy consensus tree. Here, we propose a new computational problem called the maximum greedy consensus tree problem that aims to find the most resolved greedy consensus tree. We showed that this problem is NP-hard for \(k \ge 3\). We also give a polynomial time solution when \(k=2\) and an approximation algorithm for \(k=3\).


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Authors and Affiliations

  1. 1.School of ComputingNational University of SingaporeSingaporeSingapore
  2. 2.Genome Institute of SingaporeSingaporeSingapore

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