DMTCS Proceedings, 2005 International Conference on Analysis of Algorithms

Font Size:  Small  Medium  Large

The master ring problem

Hadas Shachnai, Lisa Zhang


We consider the master ring problem (MRP) which often arises in optical network design. Given a network which consists of a collection of interconnected rings R1, …, RK, with n1, …, nK distinct nodes, respectively, we need to find an ordering of the nodes in the network that respects the ordering of every individual ring, if one exists. Our main result is an exact algorithm for MRP whose running time approaches Q·∏k=1K (nk/√2) for some polynomial Q, as the nk values become large. For the ring clearance problem, a special case of practical interest, our algorithm achieves this running time for rings of any size nk ≥2. This yields the first nontrivial improvement, by factor of (2√2)K ≈ (2.82)K, over the running time of the naive algorithm, which exhaustively enumerates all ∏k=1K (2nk) possible solutions.

Full Text: GZIP Compressed PostScript PostScript PDF original HTML abstract page

Valid XHTML 1.0 Transitional