This problem is really about understanding how DFS classifies edges based on the order in which nodes are visited. Once you map out the traversal, it becomes much easier to see which edges are tree edges and which fall into back, forward, or cross categories Dermarolling filler near me . A simple way to approach it is by keeping track of discovery and finishing times for each node. With that, the relationships become clearer, and the output rules make more sense. It’s one of those challenges where visualizing the graph can really help.