question: public String toString ( ) { StringBuilder s = new StringBuilder ( ) ; s . append ( V + " vertices, " + E + " edges " + NEWLINE ) ; for ( int v = 0 ; v < V ; v ++ ) { s . append ( v + ": " ) ; for ( int w : adj [ v ] ) { s . append ( w + " " ) ; } s . append ( NEWLINE ) ; } return s . toString ( ) ; }
target:  Returns a string representation of this graph.