c - 我需要帮助让这个程序正确打印我的输出

Question

#include <stdio.h>              /*printf and scanf option*/
#include <math.h>

void change(double coin_change, int *quarters, int *dimes, int *nickels, int *pennies);          /*function protype*/

int main(void)
{
    int fifties = 0, twenties = 0, tens = 0, fives = 0, dollars = 0, quarters = 0, dimes = 0, nickels = 0, pennies = 0;
    double amt_paid = 0, amt_due = 0, amt_change = 0, coin_change = 0;          /*declared avriables*/

    printf("Enter the amount paid> ");                  /*Prompt user to enter amount paid*/
    scanf("%lf", &amt_paid);

    printf("Enter the amount due> ");                   /*Prompt user to enter amount due*/
    scanf("%lf", &amt_due);

    amt_change = amt_paid - amt_due;                    /*Formula for amount of change to be given*/
    dollars = (amt_change);

    coin_change = (int)((amt_change - (amt_change)) * 100 + 0.5);
    coin_change = coin_change * 100;
    printf("\n%f\n", coin_change);

    change(coin_change, &quarters, &dimes, &nickels, &pennies);

    printf("Change is fifties: %d$, twenties: %d$, tens: %d$, fives: %d$, dollars: %d$, quarters: %d, dimes: %d, nickels: %d,\
           pennies: %d", fifties, twenties, tens, fives, dollars, quarters, dimes, nickels, pennies);  
    return(0);
}

void change(double coin_change, int *quarters, int *dimes, int *nickels, int *pennies)
{
    int q = 1, d = 1, n = 1, p = 1;
    do {
        if(coin_change >= 25){
            *quarters = *quarters + q;
            coin_change = coin_change - 25;
        }
        else if (coin_change >= 10) {
            *dimes = *dimes + d;
            coin_change = coin_change - 10;
        }
        else if (coin_change  >=  5) {
            *nickels = *nickels + n;
            coin_change = coin_change - 5;
        }
        else if (coin_change >= 1) {
            *pennies = *pennies + p;
            coin_change = coin_change - 1;
        }
    } while (coin_change >= 1);
}

抱歉我第一次没说清楚。我需要的是创建一个基本上是收银机程序的东西。当给出应付金额以及用户支付的金额时，我应该收到输出，告诉我我应该收到多少张 50 美元的钞票、20 美元、10 美元、5 美元、1 美元、25 美分、10 美分、5 美分和便士作为找零。由于我是编程新手，因此您所看到的代码是据我所知的。我确实需要改进甚至彻底改变它。我真正想做的是找出我的错误并改正它们。我希望尽快完成这段代码。我觉得我很接近，但只是错过了。也许我错了，但这就是我来找你们的目的。

Answer 1

有几件事:

1. 您有许多未使用的变量:五十、二十、十、五、美元 等

2. 此处的行:

   coin_change = (int)((amt_change - (amt_change)) * 100 + 0.5);
coin_change = coin_change * 100;

   错了。它们应该替换为如下内容:

   coin_change = (100 * amt_change)。

3. 您听说过 +=/-= 运算符吗？他们会改变这些行:

   *季度 = *季度 + q;
coin_change = coin_change - 25;

   进入此:

   *四分之一+= q;
coin_change -= 25;

在我修复这些问题之后，你的代码工作正常。