ATM取款机基本功能：开户登录存取款转账查询余额修改密码信息存入txt文档，密码以*显示，限定账户长度12密码长度6，存取款转账金额为50倍数分别限定最大金额。参考了网上的资料-ATM machines basic functions: login to access money transfers account balance inquiries modify password information stored in txt file, the password to* show tha