public int calculerPrix(char categorie, int jour, int age) {
        int prixTicket = -1;

        switch (categorie) {
            case 'a':
                prixTicket = 10;
                break;
            case 'b':
                prixTicket = 20;
                break;
            default:
                return prixTicket;
        }

        if(jour == 2 || jour < 1 || jour > 7) {
            return -1;
        }

        if(jour == 1) {
            prixTicket /= 5;
        } else if(jour == 6 || jour == 7) {
            prixTicket /= 2;
        }

        if(age < 10) {
            prixTicket = 0;
        } else if(age >= 60) {
            prixTicket -= 5;
        }

        return prixTicket;
    }