带变量的 C++ 幂函数

Question

#include <cstdlib>
#include <iostream>
#include <cmath>
using namespace std;

int main(int argc, char *argv[])
{
    double amount, rate, time, interest, month;
    interest = rate/(12.0*100);
    month = (amount * rate)/1.0 -(1.0 + interest), pow(time*12);
    cout << "What is the amount of the loan? $ ";
    cin >> amount;
    cout << "What is the annual percentage rate? ";
    cin >> rate;
    cout << "How many years will you take to pay back the loan?  ";
    cin >> time;
    cout <<"\n-------------------------------------------------------\n";
    cout << "Amount        Annual % Interest       Years         Monthly Payment\n\n\n";
    cout <<amount <<"                      " <<rate <<"               " <<time << "        " <<month;
    cout <<"\n\n";
    system("PAUSE");
    return EXIT_SUCCESS;
}

我在这里遇到错误，不确定如何正确使用 pow 函数。根据问题的公式为:

 Monthly payment = (loan amount)(monthly interest rate) / 1.0 - (1.0 + Monthly interest rate)^-(number of months)

这是我遇到问题的行

month = (amount * rate)/1.0 -(1.0 + interest), pow(time*12);

感谢帮助

Answer 1

std::pow 像这样接受两个参数

pow (7.0,3) 

所以你的代码应该更像这样

month = (amount * rate)/1.0 - std::pow( (1.0 + interest), 12);

您的代码还有其他缺陷，比如您在设置值之前进行了计算。