Reachable Nodes in a Directed Graph

Problem: Reachable Nodes in a Directed Graph Given a directed graph and a starting node start, return all nodes that are reachable from start. The graph may contain cycles, for example: A -> B B -> C, D D -> E E -> B Starting from A, the reachable nodes are A, B, C, D, E. Since B -> D -> E -> B forms a cycle, your traversal must avoid infinite loops. Implement a function that returns all reachable nodes. For deterministic judging, output the reachable nodes sorted in lexicographical order. Input Format n m v1 v2 ... vn u1 v1 u2 v2 ... um vm start n is the number of nodes. m is the number of directed edges. The second line contains n unique node names. The next m lines each contain two strings u v, representing a directed edge u -> v. The last line contains the starting node start. Output Format Print all nodes reachable from start, including start itself, sorted in ascending lexicographical order and separated by spaces. Constraints 1 <= n <= 10^5 0 <= m <= 2 * 10^5 Node names are non-empty strings without spaces. start is guaranteed to be one of the given nodes. The graph may be disconnected and may contain self-loops or cycles. Example Input: 5 5 A B C D E A B B C B D D E E B A Output: A B C D E Example Input 5 5 A B C D E A B B C B D D E E B A Output A B C D E