public void printBreadthFirst()
    {
		NoeudRN z= racine;
		Queue<NoeudRN> noeuds= new LinkedList<NoeudRN>();
		if(z != sentinelle){
			noeuds.add(z);
			while(!noeuds.isEmpty()){
				z= noeuds.remove();
				System.out.println(z.toString());
				if(z.getGauche() != sentinelle)
					noeuds.add(z.getGauche());
				if(z.getDroit() != sentinelle)
					noeuds.add(z.getDroit());
			}
		}
    }