Exemple #1
0
  public static Graph erdosRenyiGraph(int n, int e) {
    List<Node> nodes = new ArrayList<Node>();
    for (int i = 0; i < n; i++) nodes.add(new GraphNode("X" + i));

    Graph graph = new EdgeListGraph(nodes);

    for (int e0 = 0; e0 < e; e0++) {
      int i1 = RandomUtil.getInstance().nextInt(n);
      int i2 = RandomUtil.getInstance().nextInt(n);

      if (i1 == i2) {
        e0--;
        continue;
      }

      Edge edge = Edges.undirectedEdge(nodes.get(i1), nodes.get(i2));

      if (graph.containsEdge(edge)) {
        e0--;
        continue;
      }

      graph.addEdge(edge);
    }

    return graph;
  }
Exemple #2
0
  public static Graph weightedRandomGraph(int n, int e) {
    List<Node> nodes = new ArrayList<Node>();
    for (int i = 0; i < n; i++) nodes.add(new GraphNode("X" + i));

    Graph graph = new EdgeListGraph(nodes);

    for (int e0 = 0; e0 < e; e0++) {
      int i1 = weightedRandom(nodes, graph);
      //            int i2 = RandomUtil.getInstance().nextInt(n);
      int i2 = weightedRandom(nodes, graph);

      if (!(shortestPath(nodes.get(i1), nodes.get(i2), graph) < 9)) {
        e0--;
        continue;
      }

      if (i1 == i2) {
        e0--;
        continue;
      }

      Edge edge = Edges.undirectedEdge(nodes.get(i1), nodes.get(i2));

      if (graph.containsEdge(edge)) {
        e0--;
        continue;
      }

      graph.addEdge(edge);
    }

    for (Edge edge : graph.getEdges()) {
      Node n1 = edge.getNode1();
      Node n2 = edge.getNode2();

      if (!graph.isAncestorOf(n2, n1)) {
        graph.removeEdge(edge);
        graph.addDirectedEdge(n1, n2);
      } else {
        graph.removeEdge(edge);
        graph.addDirectedEdge(n2, n1);
      }
    }

    return graph;
  }