New function a NNI_dist(tree1, tree2) should return the minimum number of NNI steps between the two trees.
This is the minimum number of nearest neighbour interchange steps that it would take to get from tree1 to tree2. This is interesting because nni is one of the ways that search algorithms navigate tree space in order to find trees. It's the simplest of the major three methods but is still a very hard problem.
New function a NNI_dist(tree1, tree2) should return the minimum number of NNI steps between the two trees.
This is the minimum number of nearest neighbour interchange steps that it would take to get from tree1 to tree2. This is interesting because nni is one of the ways that search algorithms navigate tree space in order to find trees. It's the simplest of the major three methods but is still a very hard problem.