// A class to represent a subset for union-find
	class subset
	{
		int parent, rank;
	};


	int find(subset subsets[], int i)
	{
		// find root and make root as parent of i (path compression)
		if (subsets[i].parent != i)
			subsets[i].parent = find(subsets, subsets[i].parent);

		return subsets[i].parent;
	}


	void Union(subset subsets[], int x, int y)
	{
		int xroot = find(subsets, x);
		int yroot = find(subsets, y);

		// Attach smaller rank tree under root of high rank tree
		// (Union by Rank)
		if (subsets[xroot].rank < subsets[yroot].rank)
			subsets[xroot].parent = yroot;
		else if (subsets[xroot].rank > subsets[yroot].rank)
			subsets[yroot].parent = xroot;

			// If ranks are same, then make one as root and increment
			// its rank by one
		else
		{
			subsets[yroot].parent = xroot;
			subsets[xroot].rank++;
		}
	}


	public Vector<PathSegment> minSpanningTree()
			throws GraphException{

		Edge result[] = new Edge[vertices.size()];
		int e = 0;
		int i = 0;  // An index variable, used for sorted edges

		Vector<Edge> newEdgeList = (Vector<Edge>) edges.clone();
		Collections.sort(newEdgeList);

		subset subsets[] = new subset[vertices.size()];
		for(i=0; i<vertices.size(); i++)
			subsets[i]=new subset();

		for (int v = 0; v < vertices.size(); ++v)
		{
			subsets[v].parent = v;
			subsets[v].rank = 0;
		}

//		loop over edges
	for (Edge e1 : newEdgeList) {

//		if pair of vertices in each edge don't share a disjoint set
//		union their path segments sets and repeat
	}
	return null;
	}