Dijkstra Algorithm

package dijkstra;

import java.util.Iterator;
import java.util.PriorityQueue;

public class TestGraphs {

    public static void main(String[] args) {
        Graph g = new Graph(5);

        System.out.println("Graph:");
        // add Edges
        g.addEdge(0, 1, 5.2f);
        g.addEdge(0, 3, 12.8f);
        g.addEdge(0, 2, 10.3f);
        g.addEdge(1, 3, 5.9f);
        g.addEdge(1, 4, 15.2f);
        g.addEdge(2, 1, 1.5f);
        g.addEdge(2, 3, 2.3f);
        g.addEdge(3, 4, 8.5f);
        g.addEdge(4, 2, 2.7f);

        // print Graph
        g.printGraph();

        // Dijkstra Shortest Path Algorithm
        System.out.println("Dijkstra Shortest Path:");
        Dijkstra(g, 0);
    }

    public static void Dijkstra(Graph g, int startVertex) {
        // for storing distances after removing vertex from Queue
        float[] distances = new float[g.getvCount()];
        // for storing father id's after removing vertex from Queue
        int[] parents = new int[g.getvCount()];
        for (int i = 0; i < g.getvCount(); i++) {
            parents[i] = -1;
        }

        // set up vertex queue
        PriorityQueue<Vertex> Q = new PriorityQueue<Vertex>();
        for (int i = 0; i < g.getvCount(); i++) {
            if (i != startVertex) {
                Q.add(new Vertex(i));
            }
        }

        // add startVertex
        Vertex node = new Vertex(startVertex);
        node.setDistance(0);
        Q.add(node);

        // loop through all vertices
        while (!Q.isEmpty()) {
            // get vertex with shortest distance
            Vertex u = Q.remove();
            distances[u.getId()] = u.getDistance();

            // iterate through all neighbours
            Iterator<Edge> it = g.neighbours(u.getId()).iterator();
            while (it.hasNext()) {
                Edge e = it.next();
                Iterator<Vertex> it2 = Q.iterator();
                while (it2.hasNext()) {
                    Vertex v = it2.next();
                    // check if vertex was visited already
                    if (e.getEndPoint() != v.getId()) {
                        continue;
                    }
                    // check distance
                    if (v.getDistance() > u.getDistance() + e.getWeight()) {
                        v.setDistance(u.getDistance() + e.getWeight());
                        v.setParent(u);
                        parents[v.getId()] = v.getParent().getId();
                    }
                }
            }

        }

        // print final shortest paths
        System.out.println("Vertex\tDistance\tParent Vertex");
        for (int i = 0; i < g.getvCount(); i++) {
            System.out.println(i + "\t" + distances[i] + "\t\t" + parents[i]);
        }

    }
}