Refined Buneman Trees

Algorithm 4 Pruning the overapproximated refined Buneman tree
Require: δ is a distance matrix of size n × n
Require: T =(V,E) is an overapproximation of RB(δ)
Ensure: S is a set of splits representing RB(δ)
1: for e ∈ E do
2: Q e = ∅
3: end for
4: for (a, c) ∈ X 2 ∧ aa
10: end for
11: for each edge e on the path from a to c do
12: Q e = Q e ∪{ab e ||cd e }
13: if |Q e |≥3(n − 3) then
14: remove the n − 3 quartets with largest score from Q e
15: end if
16: end for
17: end for
18: for e ∈ E do
19: S e = ∅
20: while |S e | 0 then
32: S = S ∪ σ e
33: end if
34: end for
37