Abstract
A rings cycle is an undirected graph obtained from a cycle by replacing each edge of the cycle with a ring so that two rings corresponding to the two end-nodes of any edge have precisely one node in common. Given a weighted hypergraph on a rings cycle, Minimum-Congestion Weighted Hypergraph Embedding in a Rings Cycle (WHERC) is to embed each weighted hyperedges as a path in the rings cycle such that maximal congestion-the sum of weight of embedding paths that use any edge in the rings cycle-is minimized.We prove that the WHERC problem is NP-complete.  2-approximation algorithms are presented for the WHERC problem and a related problem-WDHETR.