Problem 1. Graph Representation Suppose a directed graph has a million nodes, most nodes have only a few edges, but a few nodes have hundreds of thousands of edges. In what way(s) would an adjacency-matrix representation of this graph lead to inefficiencies? In what way(s) would an adjacency-list representation of this graph lead to inefficiencies? . Design a representation for this sort of graph that avoids all the inefficiences in your answers to parts (a) and (b) Describe at least one situation (something being represented by a graph) where this sort of "unbal- anced" graph might arise