text: #ifndef BREADTHFIRSTSEARCH_H
  #define BREADTHFIRSTSEARCH_H
  
  #include <vector>
  #include "minimumspanningtreealgorithm.h"
  
  class BreadthFirstSearch : public MinimumSpanningtreeAlgorithm {
   public:
    std::vector<std::pair<int, int>> MinimumSpanningTree(int, const Graph&);
  
   private:
    std::vector<bool> visited;
    std::vector<int> currentlevel, nextlevel;
  };
  
  #endif /* end of include guard: BREADTHFIRSTSEARCH_H */
  