Split graph folder into graph and tree

algorithm/bfs.h

@@ -12,10 +12,12 @@ namespace algo {
 template<typename T>
 class BFS {
 public:
-  BFS(Graph<T> G) : G(G) {}
+  BFS() = default;
+
+  BFS(Digraph<T> G) : G(G) {}
 
   //
-  Digraph<T> run(const T& root);
+  std::map<T, std::set<T>> run(const T& root);
 
   // Initialize the lookup table that is used to
   // show which vertices have been traversed 
@@ -34,7 +36,7 @@ std::map<T, bool> BFS<T>::initExplore() {
 }
 
 template<typename T>
-Digraph<T> BFS<T>::run(const T& root) {
+std::map<T, std::set<T>> BFS<T>::run(const T& root) {
   std::map<T, std::set<T>> tree;
   std::map<T, bool> graphExplore = initExplore();
   std::queue<T> Q;
@@ -54,7 +56,7 @@ Digraph<T> BFS<T>::run(const T& root) {
     }
   }
 
-  return Digraph<T>(tree);
+  return tree;
 }
 
 } // namespace algo