import java.util.Iterator;

/** Demo the use of Graph interfaces and Carl* implementations.
    @author Jed Yang, 2017-01-23
*/
public class GraphDemo
{
   private final UnweightedGraph g;

   /** n is the number of vertices. */
   public GraphDemo(int n)
   {
      g = new CarlUnweightedGraph(true, n);
      g.addEdge(0, 1);
      g.addEdge(0, 2);
      g.addEdge(2, 1);
      g.addEdge(2, 0);
   }

   private void displayAdjacencyMatrix()
   {
      int n = g.numVerts();
//*
      System.out.print("   ");
      for (int j = 0; j < n; j++)
      {
         System.out.print(" " + j);
      }
      System.out.println();
      System.out.print("  +");
      for (int j = 0; j < n; j++)
      {
         System.out.print("--");
      }
      System.out.println();
//*/
      for (int i = 0; i < n; i++)
      {
         System.out.print("" + i + " | ");
         for (int j = 0; j < n; j++)
         {
            if (g.hasEdge(i, j))
            {
               System.out.print(1);
            }
            else
            {
               System.out.print(0);
            }
            System.out.print(" ");
         }
         System.out.println();
      }
   }

   private void displayStats()
   {
      int n = g.numVerts();
      for (int i = 0; i < n; i++)
      {
         System.out.println("Vertex " + i + " has degree " + g.getDegree(i)
               + " and in-degree " + g.getInDegree(i));

//*
         System.out.print("neighbours:");
         Iterable<Integer> iterable = g.getNeighbors(i);
         Iterator<Integer> iter = iterable.iterator();
         while (iter.hasNext())
         {
            System.out.print(" " + iter.next());
         }
//*
         System.out.println();
         System.out.print("for-each loop:");
         for (int v : g.getNeighbors(i))
         {
            System.out.print(" " + v);
         }
//*/
         System.out.println("\n");
      }
   }

   public void demo()
   {
      displayAdjacencyMatrix();
      displayStats();
   }

   public static void main(String[] args)
   {
      GraphDemo gd = new GraphDemo(4);
      gd.demo();
   }
}