>>406
class CreditCard{
CreditCard(const char *);
public:
static CreditCard *New(const char *name){
if(name in list){
return 0;
}
return new CreditCard(name);
}
};

CreditCard *card = CreditCard::New("岸部四郎")
if( ! card ){
　　printf("ブラックリストに載っています");
　　return 0;
}

card.buy(1000000);
delete card;
return 0;