Code for finding maximal cliques in a graph. See find_cliques_example.cpp for sample usage.

I also include some timing data in find_cliques_large_matrix.cpp, for large-ish matrices. Here is an example of the output on my system:

Matrix Size: 50, # of Cliques: 1057, Microseconds: 2023
Matrix Size: 100, # of Cliques: 3961, Microseconds: 18269
Matrix Size: 200, # of Cliques: 77603, Microseconds: 195028

The matrices in this example were randomly generated by taking each edge with probability 0.5. For most matrices the number of cliques will scale exponentially with the size of the matrix, so finding all of them is infeasible for large matrices.

If you really care about performance, you can tweak the code so that instead of a function call to check for an edge it just does a matrix lookup. This will probably speed it up around 2x.