Given a bipartite graph G and a number N, what's the minimum number of edges I have to add to G in order to be able to cover the resulting graph with no more than N complete bipartite subgraphs?
For example, consider the bipartite graph A1 - B1, A1 - B2, A1 - B3, A2 - B1, A2 - B3, A3 - B1, A3 - B2, A3 - B3, A4 - B4, A4 - B5, A5 - B4, and N = 2. The answer would be 2, because by adding A2 - B2 and A5 - B5, I can cover the graph with the biclique (A1 A2 A3 x B1 B2 B3) and (A4 A5 x B4 B5).
I can't seem to find the class of problems this is called - everything I find is about covering with subgraphs, but I actually want an over-cover while creating few extra edges. Anybody enlighten me? :)