The first picture shows the algorithm that must be used

please answer 4.2.3

172 Chapter 4 SPANNING TREES Algorithm 4.2.1: Depth-First Search Input: a connected graph G, a starting vertex v E Va Output: an ordered spanning tree T of G with root . Initialize tree T as vertex v. Initialize S as the set of proper edges incident on v. While S Let e = dfs-next Edge(G, S) Let w be the non-tree endpoint of edge e. Add edge e and vertex w to tree T. update Frontier(G, S). Return tree T