实验九

#include <bits/stdc++.h>
using namespace std;
class Account
{
private:
    double balance;
public:
    Account(double balance = 0) {balance=balance;} 
    virtual double credit(double creFee = 0)   {
        balance += creFee;
        return balance;
    }

    virtual double debit(double deFee = 0){
        if (balance >= deFee){
            balance -= deFee;
        }
        else{
            cout<<"Debit amount exceeded account balance."<<endl;
        }
        return balance;
    };

    double setBalance(double balance = 0){
        this -> balance = balance;
        return balance;
    }

    double getBalance(){
        return balance;
    }
};

class SavingsAccount : public Account
{   
    public:
        SavingsAccount(double balance = 0 ,double interestRate = 0){
            this -> interestRate = interestRate;
            setBalance(balance);
        }
        double calculateInterest() {
            return getBalance() * interestRate * 0.01;
        }
    private:
        double interestRate;
};

class CheckingAccount : public Account
{
    public:
    CheckingAccount(double balance = 0, double fee = 0){
        this -> fee = fee;
        setBalance(balance);
    }
    double credit(double creFee = 0) {
        if(getBalance() + creFee - fee >= 0)
            setBalance(getBalance() + creFee - fee);
        else 
            cout << "Transaction fee exceeded account balance while debiting." << endl;
        return 0;
    }
    double debit(double deFee = 0)
    {
        if(getBalance() - deFee - fee >= 0){
            setBalance(getBalance() - deFee - fee);
        }
        else{
            cout<<"Debit amount exceeded account balance."<<endl;
        } 
        return 0;
    }
    private:
        double fee; 
};

int main() {
    Account *accounts[3];
    accounts[0] = new SavingsAccount(100, 3);   //余额100元，利息3%
    accounts[1] = new CheckingAccount(100, 5);  //余额100元，交易费5元
    accounts[2] = new CheckingAccount(50, 5);   //余额50元，交易费5元
    for (int i = 0; i < 3; i++) {
        cout << "第" << i + 1 << "次循环的结果：" << endl;
        accounts[i]->debit(200);   //借款200元
        accounts[i]->debit(40);
        accounts[i]->credit(50);   //存款50元
        accounts[i]->debit(49);
        accounts[i]->debit(43);
        accounts[i]->credit(1);
        //将Account指针强制转换为SavingAccount指针
        SavingsAccount *derivedPtr =
        dynamic_cast<SavingsAccount *>(accounts[i]);
        if(derivedPtr != NULL)   //如果类型兼容，转换成功
        derivedPtr->credit(derivedPtr->calculateInterest());
        cout << fixed << setprecision(2);   //使用定点数格式，2位小数部分
        cout << "账户的余额为：" << accounts[i]->getBalance() << endl;
    }
}