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 |
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−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 |
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−X |
As −x but only output if two 2−paths are missed at some vertex |
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−y |
Test for decompositions using each non−triangular 3−path |
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−t# |
With −x and −X, consider only paths with center #
With −y, consider only paths starting at #
−Y |
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With −p, only consider paths whose central edge is vertical |
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−v |
Give a partition for those graphs who have one and a message for those which don’t. With −x, list exceptional 2−paths. |
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−L# |
Limit to 1000*# iterations; write with message if timeout.
Graphs that time out are written to the output.
−q |
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suppress auxiliary information |