Given n labeled vertices, there are n
n-2 different trees. The number is too large, but Wiskey want to use a way to encode the tree that make a unique sequence associated with the labeled tree.
Follow this way:
1.Select the vertex u which degree is 1 and the labeled number is the minimum. Example, u = 4.
2.Select the neighbor v of u, exists the edge which u to v. Example, v = 1.
3.Delete the edge from the tree. Example, the edge of 1-4 will be deleting.
4.Repeat the first step, until only two vertices left.
5.We will get the sequence {u1, u2… un-2} and {v1, v2… vn-2}.
Now, give you the v sequence, tell me the u sequence.