public void buildTree()
    {
        if (this.lstArbre.size() != 1) {
            Arbre a = this.minLstArbre();
            this.lstArbre.remove(a);
            Arbre b = this.minLstArbre();
            this.lstArbre.remove(b);
            Arbre i = new Arbre(a,b);
            this.lstArbre.add(i);
            
            this.buildTree();
        }
    }