计算利率

Question

所以我正在尝试为大学课程学习C ++，我必须编写一个使用这个公式的程序：

Amount = Principal * (1 + Rate/T)^T

如果本金是储蓄余额，则利率是利率，t是利息在一年内复利的次数。根据这本书，如果你输入4.25作为利率，12作为与本金复合的次数为1000.00那么你应该得到43.34作为利息，总金额应该是1043.34。我不确定我编码错了什么，但我想知道是否有人可以帮助我解决我可能犯过的任何错误！我现在试着自己做了一两天，但我没有运气。

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main()
{
    double PRINCIPAL;
    double INTEREST_RATE;
    double COMPOUND_AMOUNT;


    cout << "What is your savings account balance?: " << endl;
    cin >> PRINCIPAL;
    cout << "What is your annual interest rate?: " << endl;
    cin >> INTEREST_RATE;
    cout << "How many times has your interest been compounded?: " << endl;
    cin >> COMPOUND_AMOUNT;

    double amt1 = 1 + (INTEREST_RATE/COMPOUND_AMOUNT);
    double AMOUNT = PRINCIPAL * pow(amt1, COMPOUND_AMOUNT);

    cout << "Interest Rate: " << INTEREST_RATE << endl;
    cout << "Times Compounded: " << COMPOUND_AMOUNT << endl;
    cout << "Principal: " << PRINCIPAL << endl;
    cout << "Interest: " << INTEREST_RATE * COMPOUND_AMOUNT << endl;
    cout << "Amount: " << AMOUNT << endl;

    system("pause");
    return 0;
}

Answer 1

这是一个数学错误。如果您要将利率计算为“4.25”％，则需要将利率除以100.下面的代码在输入4.25作为利率时给出了1043.34的金额。

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main()
{
    double PRINCIPAL;
    double INTEREST_RATE;
    double COMPOUND_AMOUNT;


    cout << "What is your savings account balance?: " << endl;
    cin >> PRINCIPAL;
    cout << "What is your annual interest rate? (in %): " << endl;
    cin >> INTEREST_RATE;
    INTEREST_RATE /= 100;
    cout << "How many times has your interest been compounded?: " << endl;
    cin >> COMPOUND_AMOUNT;

    double amt1 = 1 + (INTEREST_RATE/COMPOUND_AMOUNT);
    double AMOUNT = PRINCIPAL * pow(amt1, COMPOUND_AMOUNT);

    cout << "Interest Rate (%): " << INTEREST_RATE * 100 << endl;
    cout << "Times Compounded: " << COMPOUND_AMOUNT << endl;
    cout << "Principal ($): " << PRINCIPAL << endl;
    cout << "Interest ($): " << AMOUNT - PRINCIPAL << endl;
    cout << "Amount ($): " << AMOUNT << endl;

    system("pause");
    return 0;
}

感兴趣的是你的书正在谈论美元的利息金额，即AMOUNT - PRINCIPAL。