Graph.java

package GPL;

import java.lang.Integer;
import java.util.LinkedList;
import java.util.Collections;
import java.util.Comparator;

// *************************************************************************

public class Graph {

    // Executes MSTKruskal
    public void run( Vertex s )
     {
     	System.out.println("MSTKruskal");
        Graph gaux = Kruskal();
//        Graph.stopProfile();
        gaux.display();
//        Graph.resumeProfile();
        original( s );
    }

    public  Graph Kruskal() {

        // 1. A <- Empty set
        LinkedList A = new LinkedList();

        // 2. for each vertex v E V[G]
        // 3.    do Make-Set(v)

        for ( VertexIter vxiter = getVertices(); vxiter.hasNext(); )
        {
            Vertex v = vxiter.next();
            v.representative = v; // I am in my set
            v.members = new LinkedList(); // I have no members in my set
        }

        // 4. sort the edges of E by nondecreasing weight w
        // Creates the edges objects
        //int j;
        LinkedList Vneighbors = new LinkedList();
        //Vertex u;

        // Sort the Edges in non decreasing order
        sortEdges(
            new Comparator() {
                public int compare( Object o1, Object o2 )
                 {
                Edge e1 = ( Edge )o1;
                Edge e2 = ( Edge )o2;
                if ( e1.getWeight() < e2.getWeight() )
                    return -1;
                if ( e1.getWeight() == e2.getWeight() )
                    return 0;
                return 1;
                }
        } );

        // 5. for each edge in the nondecresing order
        Vertex vaux, urep, vrep;

        for( EdgeIter edgeiter = getEdges(); edgeiter.hasNext(); )
        {
            // 6. if Find-Set(u)!=Find-Set(v)
            EdgeIfc e1 = edgeiter.next();
            Vertex u = e1.getStart();
            Vertex v = e1.getEnd();

            if ( ! ( v.representative.getName() ).equals( u.representative.getName() ) )
              {
                // 7. A <- A U {(u,v)}
                A.add( e1 );

                // 8. Union(u,v)
                urep = u.representative;
                vrep = v.representative;

                if ( ( urep.members ).size() > ( vrep.members ).size() )
                    { // we add elements of v to u
                    for( int j=0; j< ( vrep.members ).size(); j++ )
                          {
                        vaux = ( Vertex ) ( vrep.members ).get( j );
                        vaux.representative = urep;
                        ( urep.members ).add( vaux );
                    }
                    v.representative = urep;
                    vrep.representative = urep;
                    ( urep.members ).add( v );
                    if ( !v.equals( vrep ) )
                        ( urep.members ).add( vrep );
                    ( vrep.members ).clear();
                }
                else
                     { // we add elements of u to v
                    for( int j=0; j< ( urep.members ).size(); j++ )
                           {
                        vaux = ( Vertex ) ( urep.members ).get( j );
                        vaux.representative = vrep;
                        ( vrep.members ).add( vaux );
                    }
                    u.representative = vrep;
                    urep.representative = vrep;
                    ( vrep.members ).add( u );
                    if ( !u.equals( urep ) )
                        ( vrep.members ).add( urep );
                    ( urep.members ).clear();

                } // else

            } // of if

        } // of for numedges

        // 9. return A
        // Creates the new Graph that contains the SSSP
        String theName;
        Graph newGraph = new  Graph();

        // Creates and adds the vertices with the same name
        for ( VertexIter vxiter = getVertices(); vxiter.hasNext(); )
      {
            theName = vxiter.next().getName();
            newGraph.addVertex( new  Vertex().assignName( theName ) );
        }

        // Creates the edges from the NewGraph
        Vertex theStart, theEnd;
        Vertex theNewStart, theNewEnd;
        EdgeIfc   theEdge;

        // For each edge in A we find its two vertices
        // make an edge for the new graph from with the correspoding
        // new two vertices
        for( int i=0; i<A.size(); i++ )
       {
            // theEdge with its two vertices
            theEdge = ( Edge )A.get( i );
            theStart = theEdge.getStart();
            theEnd = theEdge.getEnd();

            // Find the references in the new Graph
            theNewStart = newGraph.findsVertex( theStart.getName() );
            theNewEnd = newGraph.findsVertex( theEnd.getName() );

            // Creates the new edge with new start and end vertices
            // in the newGraph
            // and ajusts the adorns based on the old edge
            // Adds the new edge to the newGraph
            // dja - the fix below fixes a bug where the proper adjust adorns gets called
//            EdgeIfc theNewEdge = newGraph.addEdge( theNewStart, theNewEnd );
//            theNewEdge.adjustAdorns( theEdge );
            Edge theNewEdge = ( Edge ) newGraph.addEdge( theNewStart, theNewEnd );
            theNewEdge.adjustAdorns( ( Edge )  theEdge );
        }
        return newGraph;

    } // kruskal

}