一个具有多态特性的银行系统程序,允许用户从帐户中存钱、取钱.功能：计算账户应得的利息，然后把利息加到帐户余额上。账户交易完之后收取费用。打印帐户余额。帐户余额不足时抛出一个异常-A program of the banking system of the multi-state characteristics, allows users to save money from the account, withdraw money. Functions: calculation of the in