循环结束后对变量值求和

Question

你好，这是我的程序的目的：

编写一个程序，计算三个月期结束时储蓄账户的余额。它应该向用户询问起始余额和年利率。然后，循环应在此期间每月迭代一次，执行以下步骤：

a）向用户索要当月存入账户的总金额，并将其添加到余额中。不接受负数。

B） 询问用户当月从账户中提取的总金额，并从余额中减去。不接受负数或当月存款加进去后大于余额的数字。

C） 计算当月的利息。月利率是年利率除以12。将月利率乘以该月起止余额的平均值，得到该月的利息金额。该金额应添加到余额中。

在最后一次迭代之后，程序应显示一个包含以下信息的报告：

• 三个月期间开始时的起始余额
• 三个月内的存款总额
• 这三个月的提款总额
• 这三个月内帐户的利息总额
• 最终余额

我遇到的问题是，在最后显示表时，我的存款、取款总额以及利息金额仅显示循环结束时的最后一个实例，而不是三个月的总金额。这是我的代码，如果不必要的复杂或混乱，请原谅。

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
//variables
double depositAmount;
double withdrawAmount;
int monthPeriod = 3;
double startBalance;
double finalBalance;
double totalBalance;
double annInterestRate;
double monthInterestRate;
double monthInterestAmount;
double monthAverageBalance;
double monthAverageAmount;
int count;

cout << "What is your starting balance?   ";
cin >> totalBalance;
cout << "What is your annual rate?  "; 
cin >> annInterestRate;

for (count = 1; count <= monthPeriod; count++)
{
    cout << "Enter total amount deposited for the month  ";
    cin >> depositAmount;
    while (depositAmount < 0)
    {
        cout << "Error, no negative amounts, please try again." << endl;
        cin >> depositAmount;
    }
    cout << "Enter total amount withdrawn for the month  ";
    cin >> withdrawAmount;
    while (withdrawAmount < 0 || withdrawAmount > totalBalance)
    {
        cout << "Error, no negative amounts or withdrawals greater than your balance. Please try    again" << endl;
        cin >> withdrawAmount;
    }
    startBalance = totalBalance + depositAmount;
    finalBalance = totalBalance - withdrawAmount;
    totalBalance = startBalance - finalBalance;
    monthInterestRate = annInterestRate * 12;
    monthAverageBalance = (startBalance + finalBalance) / 2;
    monthInterestAmount = monthAverageBalance * monthInterestRate;
    totalBalance = monthInterestAmount + totalBalance;
}
cout << "Your starting balance at the beginning of three months " << startBalance << endl;
cout << "Total deposits over three months  " << depositAmount << endl;
cout << "Total withdrawals over three months  " << withdrawAmount << endl;
cout << "Total interest posted to account over three months " << monthInterestAmount << endl;
cout << "Final Balance: " << totalBalance << endl;
cout << "Thank you for using the program!" << endl;
return 0;
}

Answer 1

这似乎是一个硬件问题，所以也许我会给出一个提示。提示：累积每月存款的变量是什么？

另外，一个不请自来的答案：您的月利率可能不是12*年利率，可能是年利率/12。希望这有所帮助。