static private void ajouterNoeud(Integer a, Integer b,TreeMap<Integer, TreeSet<Integer> > noeuds)
	 {
		 TreeSet<Integer> tmp = noeuds.get(a);
		 if(tmp == null)
		 {
			 tmp = new TreeSet<Integer>();
		 }
		 tmp.add(b);
		 noeuds.put(a, tmp);
		 
		 tmp = noeuds.get(b);
		 if(tmp == null)
		 {
			 tmp = new TreeSet<Integer>();
		 }
		 tmp.add(a);
		 noeuds.put(b, tmp);
	 }