The connected p -median problem on block graphs

In this paper, we study a variant of the p -median problem on block graphs G in which the p -median is asked to be connected, and this problem is called the connected p-median problem . We first show that the connected p -median problem is NP-hard on block graphs with multiple edge weights. Then, we propose an O ( n )-time algorithm for solving the problem on unit-edge-weighted block graphs, where n is the number of vertices in G .