class Arbre:
    def __init__(self, etiquette):
        self.v = etiquette
        self.fg = None
        self.fd = None





def ajoute(indice, element, liste):
    nbre_elts = len(liste)
    L = [0 for i in range(nbre_elts + 1)]
    if ...:
        for i in range(indice):
            L[i] = ...
        L[...] = ...
        for i in range(indice + 1, nbre_elts + 1):
            L[i] = ...
    else:
        for i in range(nbre_elts):
            L[i] = ...
        L[...] = ...
    return L