Ejemplo n.º 1
0
  /** Does not handle Graphs of 1 or fewer nodes */
  public Graph kruskal(Graph g) {
    boolean add = false;
    Graph mst = new Graph(); // initialize graph
    Vector edges = g.getEdges(); // get edges

    Collections.sort(edges); // sort edges

    // find mst
    for (int i = 0; i < edges.size(); ++i) {
      Edge edge = (Edge) edges.get(i); // get edge
      KNode[] ends = edge.getEnds(); // get ends
      if (!mst.containsNode(ends[0])) {
        mst.addNode(ends[0]); // check for first end
        add = true;
      }
      if (!mst.containsNode(ends[1])) {
        mst.addNode(ends[1]); // check other end
        add = true;
      }

      if (add) // if either end is new add edge
      {
        mst.addEdge(edge);
        add = false;
      } else // ensure trees are connected if nodes are contained
      {
        if (!mst.pathBetween(ends)) mst.addEdge(edge);
      }
    }

    return mst;
  }
Ejemplo n.º 2
0
  public Graph createGraph2() {
    Graph graph = new Graph();

    KNode n1, n2;

    n1 = new KNode("A");
    graph.addNode(n1);
    n2 = new KNode("B");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 4));

    n1 = new KNode("C");
    graph.addNode(n1);
    n2 = new KNode("D");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 7));

    n1 = new KNode("E");
    graph.addNode(n1);
    n2 = new KNode("F");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 10));

    n1 = new KNode("G");
    graph.addNode(n1);
    n2 = new KNode("H");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 1));

    n1 = new KNode("I");
    graph.addNode(n1);

    graph.addEdge(new Edge((KNode) graph.getNode("B"), (KNode) graph.getNode("C"), 8));
    graph.addEdge(new Edge((KNode) graph.getNode("D"), (KNode) graph.getNode("E"), 9));
    graph.addEdge(new Edge((KNode) graph.getNode("D"), (KNode) graph.getNode("F"), 14));
    graph.addEdge(new Edge((KNode) graph.getNode("C"), (KNode) graph.getNode("F"), 4));
    graph.addEdge(new Edge((KNode) graph.getNode("F"), (KNode) graph.getNode("G"), 2));
    graph.addEdge(new Edge((KNode) graph.getNode("B"), (KNode) graph.getNode("H"), 11));
    graph.addEdge(new Edge((KNode) graph.getNode("H"), (KNode) graph.getNode("A"), 8));
    graph.addEdge(new Edge((KNode) graph.getNode("G"), (KNode) graph.getNode("I"), 6));
    graph.addEdge(new Edge((KNode) graph.getNode("H"), (KNode) graph.getNode("I"), 7));
    graph.addEdge(new Edge((KNode) graph.getNode("C"), (KNode) graph.getNode("I"), 2));

    /*
    GRAHP:
           (B)---8---(C)---7---(D)
          / |        /  \       | \
        4   |      2     \      |  9
      /     |     /       \     |    \
    (A)     11  (I)        4    14   (E)
      \     |   /  \        \   |    /
        8   |  7    6        \  |  10
         \  | /      \        \ | /
           (H)---1---(G)---2---(F)


    MST:
           (B)---8---(C)---7---(D)
          /          /  \         \
        4          2     \         9
      /           /       \          \
    (A)         (I)        4         (E)
                            \
                             \
                              \
           (H)---1---(G)---2---(F)

    */

    return graph;
  }
Ejemplo n.º 3
0
  public Graph createGraph() {
    Graph graph = new Graph();

    KNode n1, n2;

    n1 = new KNode("A");
    graph.addNode(n1);
    n2 = new KNode("B");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 1));

    n1 = new KNode("C");
    graph.addNode(n1);
    n2 = new KNode("D");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 2));

    n1 = new KNode("E");
    graph.addNode(n1);
    n2 = new KNode("F");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 3));

    n1 = new KNode("G");
    graph.addNode(n1);
    n2 = new KNode("H");
    graph.addNode(n2);
    graph.addEdge(new Edge(n1, n2, 4));

    // box
    graph.addEdge(new Edge((KNode) graph.getNode("B"), (KNode) graph.getNode("C"), 5));
    graph.addEdge(new Edge((KNode) graph.getNode("D"), (KNode) graph.getNode("E"), 6));
    graph.addEdge(new Edge((KNode) graph.getNode("F"), (KNode) graph.getNode("G"), 7));
    graph.addEdge(new Edge((KNode) graph.getNode("H"), (KNode) graph.getNode("A"), 8));

    // cross
    graph.addEdge(new Edge((KNode) graph.getNode("A"), (KNode) graph.getNode("G"), 9));
    graph.addEdge(new Edge((KNode) graph.getNode("C"), (KNode) graph.getNode("G"), 10));
    graph.addEdge(new Edge((KNode) graph.getNode("C"), (KNode) graph.getNode("E"), 11));

    /*
    GRAPH:
    	 (A)---1---(B)---5---(C)---2---(D)
    	  | \		     / \	|
    	  |  \		    /   \	|
    	  |   \		   /	 \	|
    	  8    9         10	  11	6
    	  |      \      /	    \	|
    	  |       \    /	     \	|
    	  |        \  /		      \	|
    	 (H)---4---(G)---7---(F)---3---(E)

     MST:
    	 (A)---1---(B)---5---(C)---2---(D)
    	     		  		|
    	  		       		|
    	  	 	  		|
    	  	     		    	6
    	  	    		    	|
    	  	     		     	|
    	  			  	|
    	 (H)---4---(G)---7---(F)---3---(E)
    */

    return graph;
  }