NAME

       nauty-watercluster2 - (faster alternative to directg)

SYNOPSIS

       watercluster2 [ix] [oy] [S] [T] [B] [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.

              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, Journal of Mathematical
       Chemistry 46, 1112--1121 (2009)