C++课本第四章例题

个人银行账户管理程序

 1 #include<iostream>
 2 #include <cmath>
 3 using namespace std;
 4 class SavingsAccount{                  //储蓄账户类 
 5     private:
 6         int id;                         //账号 
 7         double balance;                 //余额 
 8         double rate;                    //存款的年利率 
 9         int lastDate;                   //上次变更余额的时期 
10         double accumulation;             //余额按日累加之和
11         //记录一笔账，date为日期，amount为金额，desc为说明
12         void record(int date,double amount);
13         //获得到指定日期为止的存款金额按日累计值
14         double accumulate(int date)const{
15            return accumulation+balance*(date-lastDate);
16         } 
17     public:
18         //构造函数
19         SavingsAccount(int date,int id,double rate);
20         int getId(){
21             return id;
22         } 
23         double getBalance(){
24             return balance;
25         }
26         double getRate(){
27             return rate;
28         }
29         void deposit(int date,double amount);           //存入现金 
30         void withdraw(int date,double amount);          //取出现金
31         //结算利息，每年一月一日调用一次该函数
32         void settle(int date);
33         //显示账户信息
34         void shouw(); 
35 }; 
36 //SavingsAccount类相关成员函数的实现
37 SavingsAccount::SavingsAccount(int date,int id,double rate):id(id),balance(0),rate(rate),lastDate(date),accumulation(0){
38     cout<<date<<"\t#"<<id<<"is created"<<endl;
39 } 
40 void SavingsAccount::record(int date,double amount){
41     accumulation=accumulate(date);
42     lastDate=date;
43     amount=floor(amount*100+0.5)/100;
44     balance+=amount;
45     cout<<date<<"\t#"<<id<<"\t"<<amount<<"\t"<<balance<<endl;
46 }
47 void SavingsAccount::deposit(int date,double amount){
48     record(date,amount);
49 }
50 void SavingsAccount::withdraw(int date,double amount){
51     if(amount>getBalance())
52     cout<<"error:not enough money"<<endl;
53     else
54     record(date,-amount);
55 }
56 void SavingsAccount::settle(int date){
57     double interest=accumulate(date)*rate/365;    //计算年息
58     if(interest!=0)
59     record(date,interest);
60     accumulation=0;
61 }
62 void SavingsAccount::shouw(){
63     cout<<"#"<<id<<"\tBalance: "<<balance<<endl;
64 }
65 int main()
66 {
67     //建立几个账户
68     SavingsAccount sa0(1,21325302,0.015);
69     SavingsAccount sa1(1,58320212,0.015);
70     //几笔账目
71     sa0.deposit(5,5000);
72     sa1.deposit(25,10000);
73     sa0.deposit(45,5500);
74     sa1.withdraw(60,4000);
75     //开户后第九十天到了银行的计息日，结算所有账户的年息
76     sa0.settle(90);
77     sa1.settle(90);
78     //输出各个账户的信息
79     sa0.shouw();
80     cout<<endl;
81     sa1.shouw();
82     cout<<endl;
83     return 0; 
84 }