Zoltan2

RCM is a serial ordering algorithm for graphs or sparse matrices. The objective is to minimize the bandwidth. This is useful for solvers, e.g. band solvers or incomplete factorizations. The algorithm is based on breadthfirst search from a root vertex. The current version finds a pseudoperipheral root (by default), and is similar to the SPARSPAK version described in George & Liu's book.
RCM expects a Zoltan2::GraphModel object. Weights are not yet supported.
TODO
An RCM solution is a permutation, currently given as a list of local ids.
RCM quality is measured by the bandwidth (not yet implemented)
TODO
Zoltan2_AlgRCM.hpp is the source file for RCB.