Here's the python-igraph code:
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import igraph
g1=igraph.Graph([(0,1),(1,0),(0,0),(1,1)],directed=True)
g2=igraph.Graph([(0,1),(1,0),(0,1),(1,0)],directed=True)
print g1.isomorphic_vf2(g2)
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the result is "True". But I think it should be 'False', and Mathematica and NetworkX both give the "False" result. A similar thing happened when I was trying to calculate the isomorphism of these following two graphs:
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g3=igraph.Graph([(0,1),(1,2),(2,0),(0,3),(3,0),(0,0),(3,3)],directed=True)
g4=igraph.Graph([(0,1),(1,2),(2,0),(0,3),(3,0),(0,3),(3,0)],directed=True)
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I don't know what's wrong. Can you please help me? Thank you!
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周达，Day Zhou
Interdisciplinary Center for Theoretical Study (ICTS)
University of Science and Technology of China (USTC)