Interface DiGraph<T>


  • public interface DiGraph<T>
    DiGraph.java Defines the Interface for a directed graph.
    Version:
    (17/3/2021)
    Author:
    (SK)
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void addArc​(T source, T destination)
      Adds an arc to the graph, from source to destination.
      void addVertex​(T vertex)
      Adds the input vertex to the graph.
      int getNumArcs()
      Returns the number of arcs in the graph
      int getNumVertices()
      Returns the number of vertices in the graph
      boolean isArc​(T vertex1, T vertex2)
      Returns true iff a directed connection exists between the two input vertices
      boolean isEmpty()
      Returns true if the graph is empty and false otherwise.
      void removeArc​(T vertex1, T vertex2)
      Removes the arc between v1 and v2.
      void removeVertex​(T vertex)
      Removes the input vertex from the graph.
      void saveToTGF​(java.lang.String tgf_file_name)
      Saves the current graph into a .tgf file.
      java.lang.String toString()
      Returns a string representation of the graph.
    • Method Detail

      • isEmpty

        boolean isEmpty()
        Returns true if the graph is empty and false otherwise.
        Returns:
        boolean True iff the graph is empty
      • getNumVertices

        int getNumVertices()
        Returns the number of vertices in the graph
        Returns:
        int The number of vertices in the graph
      • getNumArcs

        int getNumArcs()
        Returns the number of arcs in the graph
        Returns:
        int The number of arcs in the graph
      • isArc

        boolean isArc​(T vertex1,
                      T vertex2)
        Returns true iff a directed connection exists between the two input vertices
        Parameters:
        T - the first vertex
        T - the second vertex
        Returns:
        boolean true iff a directed connection exists from the first vertex to the second
      • addVertex

        void addVertex​(T vertex)
        Adds the input vertex to the graph. If the vertex already exists in the graph, the graph is not changed.
        Parameters:
        T - the vertex to be added to the graph
      • removeVertex

        void removeVertex​(T vertex)
        Removes the input vertex from the graph. If the input vertex does not belong in the graph, the graph is not changed.
        Parameters:
        T - The vertex to be removed.
      • addArc

        void addArc​(T source,
                    T destination)
        Adds an arc to the graph, from source to destination. If source or destination do not exist in the graph, the graph is not changed.
        Parameters:
        T - the source of the arc
        T - the destination of the arc
      • removeArc

        void removeArc​(T vertex1,
                       T vertex2)
        Removes the arc between v1 and v2. If v1 or v2, or the arc from v1 to v2 does not exist, the graph does not change.
        Parameters:
        T - the source of the arc to be removed
        T - the destination of the arc to be removed
      • toString

        java.lang.String toString()
        Returns a string representation of the graph.
        Overrides:
        toString in class java.lang.Object
        Returns:
        String a string representation of this graph
      • saveToTGF

        void saveToTGF​(java.lang.String tgf_file_name)
        Saves the current graph into a .tgf file.
        Parameters:
        the - name of the file to write to