1 research outputs found
A -Approximation Algorithm for Coloring Rooted Subtrees of a Degree Tree
A rooted tree is a rooted subtree of a tree if the tree
obtained by replacing the directed edges of by undirected edges is a
subtree of . We study the problem of assigning minimum number of colors to a
given set of rooted subtrees of a given tree such that if any
two rooted subtrees share a directed edge, then they are assigned different
colors. The problem is NP hard even in the case when the degree of is
restricted to . We present a -approximation algorithm for this
problem. The motivation for studying this problem stems from the problem of
assigning wavelengths to multicast traffic requests in all-optical WDM tree
networks.Comment: 16 pages, 1 figur