NAME

       nauty-watercluster2 - (faster alternative to directg)

SYNOPSIS

       watercluster2 [ix] [oy] [S] [T] [B] [Z] [C] [m]

DESCRIPTION

              Reads graphs in g6 code or multicode (optional) from stdin and directs them

              ix: the indegree of every vertex may be at most x.

              The default maximum indegree is unlimited.

              oy: the outdegree of every vertex may be at most y.

              The default maximum outdegree is unlimited.

              S : allow that for every pair of vertices x,y at most one of the edges x-->y

              and y-->x may be present. By default both of them may be present in the same graph.

              T : Output directed graphs in T-code. This is a simple ASCII output format.

              Every  line  contains  one  graph. First the number of vertices, then the number of
              directed edges and then the list of directed edges with the start first and the end
              then. E.g.: 3 2 0 1 2 1 means 3 vertices, 2 directed edges: 0-->1 and 2-->1

              B : Output the directed graphs in a binary code. Every item of the code is an

              unsigned  char.  The first unsigned char is the number nv of vertices. The vertices
              are numbered 1..nv. Then the list of vertices x for which there is a directed  edge
              1->x  follow.  This list is ended by a 0. Then the list of outgoing neighbours of 2
              follows -- again ended with a 0, etc.  The code is complete with the 0  ending  the
              list of outgoing neighbours of nv.

              Z : Output the directed graphs in digraph6 code. See formats.txt for a

              complete definition.

              C : Do really construct all the directed graphs in memory, but don't output

              them.  This  is  not  a  big  difference  in case of restricted in- and outdegrees,
              because all that is done extra is that edges are directed instead of  just  keeping
              track  of in- and out-degrees. This option is intended only for testing purposes to
              test also routines that are normally not used  when  counting.  Things  that  would
              speed  up the counting also in some cases of restricted in- and out-degrees -- like
              multiplying the possibilities of assigning directions to edges that can be assigned
              directions  independent  of each other (depending on the degrees of the endvertices
              and overlaps) -- are not included.  In case of not restrictive bounds  on  the  in-
              and out-degree it not really constructing the graphs can be considerably faster. In
              cases of restricted in- and out-degrees the only difference is that the graph isn't
              modified.   The  fact that in case of no output the graph is not modified is mainly
              to save  time  for  the  one  case  of  waterclusters,  where  large  numbers  were
              determined.  If large numbers (without output) for other cases shall be determined,
              one should think about adding the multiplication routines.

              m : read multicode instead of g6 code

       This program uses different labelling routines -- all based on the ideas of

       G. Brinkmann, Generating water clusters and other directed graphs,mJournal of Mathematical
       Chemistry 46, 1112--1121 (2009)