计算利率

Question

所以我想学习C++的大学课程，我必须写一个使用这个公式的程序：

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

其中主要是储蓄的平衡，利率是利率， t是一年内利息的复合次数。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1000.00，那么你应该得到43.34利息，总金额应该是1043.34。我不确定我是否编码错了，但我想知道是否有人可以帮我解决我可能犯的错误！我试图自己做一两天，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。如果您要将利率作为“4.25％”，则需要将利率除以100.下面的代码给出的数额为1043.34，当输入4.25作为利率时。

#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，您的书正在谈论美元的利息金额，即AMOUNT - PRINCIPAL。