public void createGraph() {
int N = 100;
int T = 10;
int x = 0;
int y = 0;
Random rando = new Random();
ArrayList<String> usedPositions = new ArrayList();
// Create vertices
for (int i = 0; i < N; i++) {
do {
x = rando.nextInt(100) + 1;
y = rando.nextInt(100) + 1;
} while (usedPositions.contains(x + "," + y));
usedPositions.add(x + "," + y);
graph.insertVertex(new Node(x, y));
}
// Create edges
// n^2
for (Graph.Vertex v1 : graph.getVertices()) {
for (Graph.Vertex v2 : graph.getVertices()) {
Node n1 = (Node) v1.getElement();
Node n2 = (Node) v2.getElement();
if (n1.equals(n2)) {
continue;
}
double distance = Math.sqrt(Math.pow((n1.x - n2.x), 2) + Math.pow((n1.y - n2.y), 2));
if (distance <= T) {
if (graph.insertEdge(distance, v1, v2)) {
// plotter.connectCircles(plotter.getCircles().get(n1.index),
// plotter.getCircles().get(n2.index));
plotter.drawLine(n1.x, n1.y, n2.x, n2.y);
// System.out.println("(" + n1.x + "," + n1.y + ")" + "," + "(" + n2.x + "," + n2.y +
// ")");
}
}
}
}
}
private void populateLists(List<Vertex> verticies, List<Edge> edges) {
for (Vertex v : graph.getVertices()) {
verticies.add(v);
}
for (Edge e : graph.getEdges()) {
edges.add(e);
}
}
public boolean findCycle(Graph graph) {
if (graph.isEmpty()) throw new RuntimeException("Graph is empty.");
/** Unvisited vertices * */
List<Integer> whiteSet = new ArrayList<>();
whiteSet.addAll(graph.getVertices());
/** Under-process vertices * */
List<Integer> graySet = new ArrayList<>();
/** Visited including adjacent vertices & children * */
List<Integer> blackSet = new ArrayList<>();
/** Call DSF of white set element * */
while (!whiteSet.isEmpty())
/** Call dfs to explore vertex and find loop * */
if (dfs(whiteSet.get(0), whiteSet, graySet, blackSet, graph)) return true;
return false;
}
/**
* Helper method for parseQuery. Writes the results of the queries to the output file.
*
* @param output initialized BufferedWriter for the output file
* @param g initialized graph of edges and vertices
* @param u1 one vertex used in commands
* @param u2 another vertex used in commands
* @param command command to execute
*/
private static void printResults(
BufferedWriter output, Graph g, Vertex u1, Vertex u2, String command) {
final String commonInfluencers = "commonInfluencers";
final String numRetweets = "numRetweets";
final String VERTEX_NOT_FOUND_ERROR =
"ERROR: One or more vertices does not exist in the graph.";
final String INVALID_COMMAND_ERROR = "\tError: invalid command ";
final String PATH_NOT_FOUND_ERROR = "\tPath not found.";
List<Vertex> allVertices = new ArrayList<Vertex>(g.getVertices());
try {
output.write("query: " + command + " " + u1.toString() + " " + u2.toString());
output.newLine();
output.write("<result>");
output.newLine();
// check if vertices exist in graph
if (!allVertices.contains(u1) || !allVertices.contains(u2)) {
output.write(VERTEX_NOT_FOUND_ERROR);
output.newLine();
output.write("</result>");
output.newLine();
output.newLine();
return;
}
// if query is commonInfluencers
if (command.equals(commonInfluencers)) {
List<Vertex> commonFollowers =
new LinkedList<Vertex>(Algorithms.commonDownstreamVertices(g, u1, u2));
for (Vertex v : commonFollowers) {
output.write("\t" + v.toString());
output.newLine();
}
}
// if query is numRetweets
else if (command.equals(numRetweets)) {
// note switch in u1 and u2; this is because tweets go upstream
int distance = Algorithms.shortestDistance(g, u2, u1);
if (distance == -1) {
output.write(PATH_NOT_FOUND_ERROR);
} else {
// implicitly convert distance to string as printing out ints somehow didn't work
output.write("" + distance);
// System.out.println(distance);
}
output.newLine();
} else {
output.write(INVALID_COMMAND_ERROR + command);
output.newLine();
}
output.write("</result>");
output.newLine();
output.newLine();
} catch (Exception e) {
throw new RuntimeException(e);
}
}