This paper presents a polynomial-time algorithm for the minimum-weight
-cycle problem on graphs that decompose via 3-separations into well-st
ructured graphs. The problem is NP-hard in general. Graphs that decomp
ose via 3-separations into well-structured graphs include Halin, outer
-facial, delta-wye, wye-delta, flat, and twirl-wheel graphs. For each
of these classes of graphs, given the decomposition, the algorithm run
s in linear time. (C) 1997 Jonn Wiley & Sons, Inc.