/'(Connected) Component of an undirected G: = the maximal connected subgraph D' A tree: :=a graph that is connected and acyclic D ADAG: :=a directed acyclic graph y' Strongly connected directed graph G: =for every pair of vi and v, in V(G), there exist directed paths from v, to v, and from v; to v;. If the graph is connected without direction to the edges, then it is said to be weakly connected y Strongly connected component: the maximal subgraph that is strongly connected y Degree(v): : =number of edges incident to v. For a directed G, we have in-degree and out-degree. For example: in-degree(v)=3; out-degree(v)=l; degree(v)=4 y Given G with n vertices and e edges, then e=∑a/ where d,=cgre(n) (Connected) Component of an undirected G ::= the maximal connected subgraph  A tree ::= a graph that is connected and acyclic  Strongly connected directed graph G ::= for every pair of vi and vj in V( G ), there exist directed paths from vi to vj and from vj to vi . If the graph is connected without direction to the edges, then it is said to be weakly connected  Strongly connected component ::= the maximal subgraph that is strongly connected  Degree( v ) ::= number of edges incident to v. For a directed G, we have in-degree and out-degree. For example: v in-degree(v) = 3; out-degree(v) = 1; degree(v) = 4  Given G with n vertices and e edges, then 2 where degree( ) 1 0 i i n i i e d  d = v      =  − =  A DAG ::= a directed acyclic graph