public void printMergedNodes() {
		Iterator<Integer> it = mergedNodes.keySet().iterator();
		while (it.hasNext()) {
			int vertex = it.next();
			System.out.print(vertex + ":");
			LinkedList<Integer> nodes = mergedNodes.get(vertex);
			if (nodes != null) {
				System.out.print("[");
				for (int i : nodes) {
					System.out.print(i + ",");
				}
				System.out.println("]");
			} else {
				System.out.println("null!!");
			}
		}
	}