On the maximum locally clustered subgraph and some related problems

Abstract

Motivated by detecting false friend links in online social networks, we define two optimization problems based on the balance theory for structural transitivity in social networks. We give a polynomial time algorithm for one problem and show the NP-hardness of the other. For the NP-hard problem, we show some polynomial time solvable cases and give a 2-approximation algorithm for a restricted version. We also propose a heuristic algorithm for a more general version of the problem. © 2011 Springer-Verlag.