The 2-center Problem in Maximal Outerplanar Graph

We consider the problem of computing 2-center in maximal outerplanar graph. In this problem, we want to find an optimal solution where two centers cover all the vertices with the smallest radius. We provide the following result. We can compute the optimal centers and the optimal radius in $O(n^2)$ time for a given maximal outerplanar graph with $n$ vertices. We try to let the maximal outerplanar graph be cut into two subgraphs with an internal edge, each center will cover vertices which are continuous.