Question

write a program in C that determines the change to be dispensed from a vending machine. An item in the machine can cost between 25 cents and a dollar, in a 5-cent increments(25,30,35.....,90,95,or 100), and the machine accepts only a single dollar bill to pay for the item.

for example a possible dialogue with the user might be

"Enter price of item (from 25 cents to a dollar, in 5-cent increments):45

you boughtan item for 45 cents and gave me a dollar.

so your change is

2 quarters,

0 dimes, and

1 nickles."

include input checking. Display the change only if the valid price is entered (no less than 25 cents no more than 100 cents, and an integer multiple of 5 cents). otherwise display seperate error messages for any of the following invalid inputs: a cost under 25 cents, a cost that is not an integer multiple of 5, and a cost that is more than a dollar.   

Be sure to use the proper heading content and layout (heading.txt)

Be sure to update the name, date, and documentation information.

Calculations should be separate statements, not placed in the print statement.

The user will enter the cost of the item (integer)

Validate the cost value and display any needed message according to the project instructions.

The program will produce output similar to what is shown on page 132.

Additional instruction: When the value of a coin denomination is zero, do not print the information for that coin.

Using this at the base.

DOCUMENTATION
Page ?, programming project #?
This program
******************************************************************************/

import java.util.Scanner;

public class program##
{
   public static void main(String[] args)
   {
       enter code here
   }
}

Answer 1

CODE:

#include<stdio.h>
#include<conio.h>

void main(){
  
   int price;
   printf("Enter price of item (from 25 cents to a dollar, in 5-cent increments): ");
   scanf("%d", &price);
  
   while(price < 25 || price > 100 || price % 5 != 0){//get the input from user until he enters a valid price
       if(price < 25){
           printf("\n\nPlease enter a valid price greater than equal to 25 cents.");
       }else if(price > 100){
           printf("\nPlease enter a valid price lesser than 100 cents.");
       }else{
           printf("\nPlease enter a price which is a multiple of 5.");
       }
       scanf("%d", &price);
   }
  
   //got the valid price from user
   printf("\n\nyou bought item for %d cents and gave me a dollar.\n", price);
  
   int difference = 100 - price;
  
   if(difference == 0)//nothing to return
   {
       printf("\nNo change needed for return.");
   }
   else{
   int quartersToReturn = difference / 25;
   difference = difference % 25;
  
   int dimesToReturn = difference/10;
   difference = difference % 10;
  
   int nicklesToReturn = difference/5;
   difference = difference % 5;
  
   int centsToReturn = difference;
  
   printf("\n\nYour change is:");
  
   if(quartersToReturn != 0)
   printf("\n %d Quarters", quartersToReturn);
  
   if(dimesToReturn != 0)
   printf("\n %d Dimes", dimesToReturn);
  
   if(nicklesToReturn != 0)
   printf("\n %d Nickles", nicklesToReturn);
  
   if(centsToReturn != 0)
   printf("\n %d Cents", centsToReturn);
  
   }
  
  
   getch();
}

SCREENSHOTS:

OUTPUT:

In case of any doubts, do let me know in the comments section and I'll get those resolved :)