Provided by: nauty_2.6r10+ds-1_amd64 bug


       nauty-twohamg - split quartic graphs into two hamiltonian cycles


       twohamg [-sgvq] [-L#] [infile [outfile]]


              Partition quartic graphs into two hamiltonian cycles.

              Output those which cannot be partitioned.

       -s     force output to sparse6 format

       -g     force  output  to graph6 format If neither -s or -g are given, the output format is
              determined by the header or, if there is none, by the format  of  the  first  input
              graph. Also see -S.

              The output file will have a header if and only if the input file does.

       -p     Read a cubic graph and use its prism. Vertex i of the input becomes

              vertices 2*i,2*i+1 in the prism.

       -x     Test for decompositions using each 2-path

       -X     As -x but only output if two 2-paths are missed at some vertex

       -y     Test for decompositions using each non-triangular 3-path

       -t# With -x and -X, consider only paths with center #

              With -y, consider only paths starting at #

       -Y     With -p, only consider paths whose central edge is vertical

       -v     Give a partition for those graphs who have one and a message for those which don't.
              With -x, list exceptional 2-paths.

       -L# Limit to 1000*# iterations; write with message if timeout.

              Graphs that time out are written to the output.

       -q     suppress auxiliary information