Heinz Koeppl, Marc Hafner, et al.
BMC Bioinformatics
We discuss the problem of ranking nodes of a tree, which is a restriction of the general node coloring problem. A tree is said to have rank number k if its vertices can be ranked using the integers 1, 2,...,k such that if two nodes have the same rank i, then there is a node with rank greater than i on the path between the two nodes. The optimal rank number of a tree gives the minimum height of its node separator tree. We present an O(n log n) algorithm for optimal node ranking of trees. © 1988.
Heinz Koeppl, Marc Hafner, et al.
BMC Bioinformatics
Sabine Deligne, Ellen Eide, et al.
INTERSPEECH - Eurospeech 2001
Maurice Hanan, Peter K. Wolff, et al.
DAC 1976
M.F. Cowlishaw
IBM Systems Journal