A directed rooted graph is defined as graph for which there exists a vertex r such that to every vertex x there is a unique path (Equivalently dfs tree with source r has only back edges and has all vertices). I need an algorithm to find the longest path in such a graph.I know that in general longest path problem is NP-hard. I want to know whether for this special case there exists a polynomial time algorithm.
Longest Path in a directed rooted graph
algorithms;graphs