class indivisualvertex implements Comparable<indivisualvertex> {

int data;                                  //data associated with the vertex
double distanceFromSource;                 //will store the distances from the source vertex
int previousVertexOnShortestPathFromSource;//will store the previous vertex on the path
neighbours adjacentPointsList;             // neighbouring vertices stored in a linked list



//for sorting the vertices in the priority queue according to their distances from the source
public int compareTo(indivisualvertex other) {
    if (this.equals(other)) {
        return 0;
    } else if (this.distanceFromSource > other.distanceFromSource) {
        return 1;
    } else {
        return -1;
    }

}
}

private void relax(indivisualvertex indx) {

 //traverse the neighbouring edges
 for (neighbours nbr = indx.adjacentPointsList; nbr != null; nbr = nbr.next){

        //condition where a vertex is unvisited and also provides a shorter path
        if (visited[nbr.pointer_of_vertex] == false && vertices[nbr.pointer_of_vertex].distanceFromSource > vertices[nbr.from].distanceFromSource + nbr.weight) {
            pq.remove(vertices[nbr.pointer_of_vertex]);
            vertices[nbr.pointer_of_vertex].distanceFromSource = vertices[nbr.from].distanceFromSource + nbr.weight;
            vertices[nbr.pointer_of_vertex].previousVertexOnShortestPathFromSource = nbr.from;
            pq.add(vertices[nbr.pointer_of_vertex]);
        }
    }
}