A lower bound for 3-Clique
We will (recap the) proof of

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Do you ever tried to use the Boost C++ graph library (abr. BGL) with the vertices stored within a list (listS) instead of a vector (vecS)? Then you might have figured out that most algorithms requiring an index map which maps the vertices to integer values in the range 0, …, num_vertices(G)-1. How to deal with this issue? For a very smart answer check out #5 at the Boost graph library FAQ.