Mathematics
Graph Isomorphism and the Graph Isomorphism Problem
Quick fact
The graph isomorphism problem is famously neither known to be solvable in polynomial time nor known to be NP-complete, making it one of the few natural problems with this ambiguous status.
Why this is interesting
You’ve probably seen a graph redrawn with different labels and wondered if it’s really the same graph. How can we tell if two graphs are the same shape?