Finding Connected-Dense-Connected (CDC) subgraphs from Triple Networks is NP-Hard. finding One-Connected-Dense (OCD) sub- graphs from Triple Networks is also NP-Hard. We present formal proofs of these theorems hereby.
Shah, Dhara; Prasad, Sushil; and Wu, Yubao, "Finding Connected-Dense-Connected Subgraphs and variants is NP-Hard" (2019). Computer Science Technical Reports. 2.