visited truev low num counter++/rule for each vertex adjacent to if! visited /forward edge parent vfindartw )ifw low > num cout < <is an articulation point<endlv low minv loww low )/rule else ifv parent ! /back edge low minv loww num )/rule figure testing for articulation points in one depth-first search (test for the root is omitted(pseudocodefigure three drawings figure conversion of puzzle to graph