1Null graph: 2( ) 3 4Singleton graph: 5( 0 ) 6 7Path with isolated vertex: 8( 1 0 1 ) 9 10Undirected path graph: 11( 4 3 2 3 4 ) 12 13Directed path graph: 14( 4 3 2 1 0 ) 15 16Undirected star: 17( 1 2 2 2 2 2 2 2 2 2 ) 18 19Out-star: 20( 1 2 2 2 2 2 2 2 2 2 ) 21 22In-star: 23( 1 0 0 0 0 0 0 0 0 0 ) 24