Question

• develop an algorithm and then a C program that accomplishes the following.
  • determines the minimum number of quarters, dimes, nickels, and pennies to make change for any amount of cents from 1 cent to 99 cents inclusive;
  • produces an error message if 0 or more than 99 is entered as input, but the program will keep running and ask for another input;
  • terminate if 0 or a negative number is entered.
  • Here is possible example of the program running (remember that there could be any number of inputs (perhaps 1,000,000) but all inputs are integers)

Hints: use if / else if / else... use % and /... use a while loop or a do while loop, no arrays

example:

Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  31
             Quarters: 1   Dimes: 0   Nickels: 1   Pennies: 1
               Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  89
               Quarters: 3 Dimes: 1 Nickels: 0 Pennies: 4
               Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  121
   Your entered a value outside the range.
               Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  0
   Your entered a value outside the range.
               Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  18
               Quarters: 0 Dimes: 1 Nickels: 1 Pennies: 3
   Your entered a value outside the range.
               Please enter the number of cents, from 1 through 99, or enter a negative number to quit:  -666   
               Thanks for using my program. Good bye.

Answer 1

program:

#include <stdio.h>
#include <stdlib.h>
int main()
{
        int amount; /* how much change the user has */
    int leftover; /* used to hold amount as it decreases */
    int numquarters; /* how many quarters */
    int numdimes; /* how many dimes */
    int numnickels; /* how many nickels */
    int numpennies; /* how many pennies */

    /* read in the amount and save it */
    printf("Please enter the number of cents, from 1 through 99, or enter a negative number to quit:");
    scanf("%d", &amount);
    while(amount>=0)
    {
       if(amount == 0 || amount>99)
       {
           printf("Your entered a value outside the range.\n");
       }
       else
       {
           leftover = amount;
           /* computer the number of quarters and how much is left over */
           numquarters = leftover / 25;
           leftover = leftover % 25;
           /* computer the number of dimes and how much is left over */
           numdimes = leftover / 10;
           leftover = leftover % 10;
           /* computer the number of nickels and how much is left over */
           numnickels = leftover / 5;
           leftover = leftover % 5;
           /* whatever is left over is the number of pennies */
           numpennies = leftover;
           /* print the result */
           printf("Quarters: %d Dimes: %d Nickels: %d Pennies: %d\n", numquarters, numdimes, numnickels, numpennies);
       }
       printf("Please enter the number of cents, from 1 through 99, or enter a negative number to quit:");
       scanf("%d", &amount);
   }
   printf("Thanks for using my program. Good bye.");
}

output: