public static HashSet<String>[] filterStartingNodes(Graph[] g, int thresh)
	{
		int i=0;
		HashSet<String>[] startingNodes=new HashSet[g.length];
		for(i=0;i<g.length;i++)
		{
			startingNodes[i]=new HashSet<String>();
			HashMap<String,Node> mapNodes=g[i].getMapNodes();
			Iterator<String> it=mapNodes.keySet().iterator(); 
			while(it.hasNext())
			{
				String id=it.next();
				int degree=mapNodes.get(id).degree();
				if(degree>=thresh)
					startingNodes[i].add(id);
			}
			//System.out.println(startingNodes[i].size());
		}
		return startingNodes;
	}