C++代码源自《C++语言程序设计(第4版)》(清华大学计算机系列教材) 郑莉, 董渊, 何江舟 清华大学出版社
5_11
C++源码
//5_11.cpp
#include "account.cpp"
#include <iostream>
using namespace std;
int main() {
//建立几个账户
SavingsAccount sa0(1, 21325302, 0.015);
SavingsAccount sa1(1, 58320212, 0.015);
//几笔账目
sa0.deposit(5, 5000);
sa1.deposit(25, 10000);
sa0.deposit(45, 5500);
sa1.withdraw(60, 4000);
//开户后第90天到了银行的计息日,结算所有账户的年息
sa0.settle(90);
sa1.settle(90);
//输出各个账户信息
sa0.show(); cout << endl;
sa1.show(); cout << endl;
cout << "Total: " << SavingsAccount::getTotal() << endl;
return 0;
}
//account.cpp
#include "account.h"
#include <cmath>
#include <iostream>
using namespace std;
double SavingsAccount::total = 0;
//SavingsAccount类相关成员函数的实现
SavingsAccount::SavingsAccount(int date, int id, double rate)
: id(id), balance(0), rate(rate), lastDate(date), accumulation(0) {
cout << date << " #" << id << " is created" << endl;
}
void SavingsAccount::record(int date, double amount) {
accumulation = accumulate(date);
lastDate = date;
amount = floor(amount * 100 + 0.5) / 100; //保留小数点后两位
balance += amount;
total += amount;
cout << date << " #" << id << " " << amount << " " << balance << endl;
}
void SavingsAccount::deposit(int date, double amount) {
record(date, amount);
}
void SavingsAccount::withdraw(int date, double amount) {
if (amount > getBalance())
cout << "Error: not enough money" << endl;
else
record(date, -amount);
}
void SavingsAccount::settle(int date) {
double interest = accumulate(date) * rate / 365; //计算年息
if (interest != 0)
record(date, interest);
accumulation = 0;
}
void SavingsAccount::show() const {
cout << "#" << id << " Balance: " << balance;
}
//account.h
#ifndef __ACCOUNT_H__
#define __ACCOUNT_H__
class SavingsAccount { //储蓄账户类
private:
int id; //账号
double balance; //余额
double rate; //存款的年利率
int lastDate; //上次变更余额的时期
double accumulation; //余额按日累加之和
static double total; //所有账户的总金额
//记录一笔帐,date为日期,amount为金额,desc为说明
void record(int date, double amount);
//获得到指定日期为止的存款金额按日累积值
double accumulate(int date) const {
return accumulation + balance * (date - lastDate);
}
public:
//构造函数
SavingsAccount(int date, int id, double rate);
int getId() const { return id; }
double getBalance() const { return balance; }
double getRate() const { return rate; }
static double getTotal() { return total; }
//存入现金
void deposit(int date, double amount);
//取出现金
void withdraw(int date, double amount);
//结算利息,每年1月1日调用一次该函数
void settle(int date);
//显示账户信息
void show() const;
};
#endif //__ACCOUNT_H__
C++运行结果
Java代码
//Test.java
public class Test {
public static void main(String[] args) {
SavingsAccount sa0=new SavingsAccount(1, 21325302, 0.015);
SavingsAccount sa1=new SavingsAccount(1, 58320212, 0.015);
//几笔账目
sa0.deposit(5, 5000);
sa1.deposit(25, 10000);
sa0.deposit(45, 5500);
sa1.withdraw(60, 4000);
//开户后第90天到了银行的计息日,结算所有账户的年息
sa0.settle(90);
sa1.settle(90);
//输出各个账户信息
sa0.show(); System.out.println();
sa1.show(); System.out.println();
System.out.println("Total: " + SavingsAccount.getTotal());
}
}
//SavingsAccount.java
public class SavingsAccount {
private int id; //账号
private double balance; //余额
private double rate; //存款的年利率
private int lastDate; //上次变更余额的时期
private double accumulation; //余额按日累加之和
private static double total; //所有账户的总金额
//记录一笔帐,date为日期,amount为金额,desc为说明
private void record(int date, double amount) {
accumulation = accumulate(date);
lastDate = date;
amount =Math.floor((amount * 100 + 0.5)/100);//保留小数点后两位
balance += amount;
total += amount;
System.out.println(date+" #"+id+" "+ amount+" "+ balance);
}
//获得到指定日期为止的存款金额按日累积值
private final double accumulate(int date) {
return accumulation + balance * (date - lastDate);
}
//构造函数
SavingsAccount(int date, int id, double rate) {
this.id=id;
this.balance=0;
this.rate=rate;
this.lastDate=date;
this.accumulation=0;
System.out.println( date+" #"+id + " is created" );
}
int getId() { return id; }
double getBalance() { return balance; }
double getRate() { return rate; }
static double getTotal() { return total; }
//存入现金
void deposit(int date, double amount) {
record(date, amount);
}
//取出现金
void withdraw(int date, double amount) {
if (amount > getBalance())
System.out.println( "Error: not enough money
");
else
record(date, -amount);
}
//结算利息,每年1月1日调用一次该函数
void settle(int date) {
double interest = accumulate(date) * rate / 365; //计算年息
if (interest != 0)
record(date, interest);
accumulation = 0;
}
//显示账户信息
void show() {
System.out.println("#" + id + " Balance: " + balance);
}
}