graph algorithms / / / / / / / figure depth-first tree that results if depth-first search starts at we close by giving pseudocode to implement this algorithm we will assume that vertex contains the data members visited (initialized to false)numlowand parent we will also keep (graphclass variable called counterwhich is initialized to to assign the preorder traversal numbersnum we also leave out the easily implemented test for the root as we have already statedthis algorithm can be implemented by performing preorder traversal to compute num and then postorder traversal to compute low third traversal can be used to check which vertices satisfy the articulation point criteria performing three traversalshoweverwould be waste the first pass is shown in figure the second and third passeswhich are postorder traversalscan be implemented by the code in figure the last if statement handles special case if is adjacent to /*assign num and compute parents *void graph::assignnumvertex num counter++ visited truefor each vertex adjacent to if! visited parent vassignnumw )figure routine to assign num to vertices (pseudocode