Graph of network The graph of network is simply a diagram showing the interconnection of network elements, in this diagram every two- terminal network element is represented, regardless of its nature, by a line segment called a branch, and each end point of element is denoted by a dot called a node. The collection (A) of these branches and nodes is called the graph of the network nl if b2 (directed grapGraph of network The graph of network is simply a diagram showing the interconnection of network elements, in this diagram every two￾terminal network element is represented, regardless of its nature, by a line segment called a branch, and each end point of element is denoted by a dot called a node. The collection （集合） of these branches and nodes is called the graph of the network. 1 b b2 3 b 4 b 5 b 6 b 7 b n2 n1 n0 n4 n3 n5 (directed graph) n2 1 b 2 b 3 b 4 b 5 b 6 b 7 b n1 n0 n3 n4 5 n