c - 是/否提示重新运行程序

Question

我希望我的程序有一个是或否提示来询问程序是否应该再次运行。现在，它完全跳过用户输入。我怎样才能有效地做到这一点？

如有任何帮助，我们将不胜感激。谢谢!

#include <stdio.h>
#include <math.h>

double Months(double principal,double annualInterestRate,double monthlyPayment)
{
    double x = ((log(monthlyPayment)-log(monthlyPayment-annualInterestRate/1200.0*principal))/log(annualInterestRate/1200.0+1.0));
    return x;
}

int calculateMonths(double y)
{
    double principal, annualInterestRate, monthlyPayment;
    y = Months(principal, annualInterestRate, monthlyPayment);
    return y;
}

int main()
{
    double principal, annualInterestRate, monthlyPayment;
    char response = 'Y';


    printf("** Welcome to the CPSC 1010-S3 Payment Calculator **\n\n");

    do{
         printf("Enter the principal amount:\t\t\t");
         scanf("%lf", &principal);

         printf("Enter the annual interest rate (in%%):\t\t");
         scanf("%lf", &annualInterestRate);

         printf("Enter the monthly payment:\t\t\t");
         scanf("%lf", &monthlyPayment);

         printf("\nCalculating...\n\n");

         int roundedMonths = Months(principal, annualInterestRate, monthlyPayment)+.5;
         printf("Total # of months needed to pay off:\t\t %d\n", roundedMonths);

         double years = Months(principal, annualInterestRate, monthlyPayment)/12;
         printf("Approcimate # of years needed to pay off: \t %.1f\n", years);

         double amountPaid = roundedMonths * monthlyPayment;
         double interestPaid = amountPaid-principal;

         printf("Total interest paid:\t\t\t\t $%.2f\n", interestPaid);
         printf("Total amount paid:\t\t\t\t $%.2f\n", amountPaid);

         double overpay = amountPaid - Months(principal, annualInterestRate, monthlyPayment)*monthlyPayment;
         printf("You overpaid:\t\t\t\t $%.2f\n", overpay);

         int extraMonthlyPayment = monthlyPayment*.1;
         int monthsEarly = ((log((monthlyPayment*1.1))-log((monthlyPayment*1.1)-annualInterestRate/1200.0*principal))/log(annualInterestRate/1200.0+1.0));
         int newMonths = Months(principal, annualInterestRate, monthlyPayment)-monthsEarly;

         printf("Did you know if you paid an additional $%d per month, you would pay off your loan %d months earlier?\n\n", extraMonthlyPayment, newMonths);

         printf("Do you wish to calculate another payoff? (Y/N):\t");
         scanf("%c", &response);

    }
    while(response == 'Y' || response == 'y');

    printf("Thank you for using the Payment Calculator!\n\n");


    return(0);
}

Answer 1

使用 scanf 不是最佳选择。

我想添加一个

while (getchar());

最后一个 scanf 之前的行。

请确保您不会因输入缓冲区中的换行符而丢失或损坏其他数据。