Problem · problem
Graph isomorphism complexity
It is one of very few natural problems that is in NP but believed to be neither in P nor NP-complete. Babai's quasipolynomial algorithm was the biggest advance in decades. A bug found in 2017 was fixed within days. Whether polynomial time is possible is open.
Closed 2015, László Babai: quasipolynomial time.
Sources
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