/*  Program: Project1 (Simple Vending Machine)
    Author: Hei-Wah Leung
    Class: CSCI 110
    Date: 9-22-2003
    Description: The vending machine wil only accept one dollar bill. 
	             The program would read an integer value between 
				 0 and 3. Then the machine will calculates and return the change.

    I certify that:

       - All code used in my program is either my original work or was
         %ified by me from the source code published in the text of
         this course or provided by my instructor.

       - I have not used code obtained from another student, or any other
         unauthorized source, either %ified or un%ified.

       - I have not discussed or shared coding details of this program
         with anyone other than my instructor or MT. SAC tutors.  I
         understand that I may discuss the concepts/ideas of this program
         with other students as long as we do not get down to the coding
         details.                                                           */

#include <stdio.h>

main ()
{
	int quarter, dime, nickel, penny, amount, x, y, c1, c2, c3, c4;
	while(amount !=-1){
	printf("Enter a purchase amount [0 - 100] or type -1 to exit: ");
	scanf("%d",&amount);
	if(amount == -1){
		printf("This program is written by Chi Tat Leung.\n");
		printf("Thank you for using this program.\n");
	}
	else if (amount <= 0){
		printf("No more purchase. Good bye.\n");
		printf("\n");
	}
	else if (amount > 100){
		printf("The amount you entered is invaild. Please try again.\n");
		printf("\n");			
	}
		else{
			printf("You entered a purchase amount of %d cents.\n",amount);
			y = amount;
			x = 100 - y;
			quarter = x / 25;
			amount = x % 25;
			c1 = quarter * 25;

            y = amount;
			dime = amount / 10;
    		amount = amount % 10;
    		c2 = dime * 10;

			y = amount;
			nickel = amount / 5;
			penny= amount % 5;
			c3 = nickel * 5;
			c4 = penny * 1;
		
			printf("Your change of %d cents is given as:\n",x);
			printf("	%d quarters (%d cents)\n",quarter,c1);
			printf("	%d dimes (%d cents)\n",dime,c2);
			printf("	%d nickels (%d cents)\n",nickel,c3);
			printf("	%d pennies (%d cents)\n",penny,c4);
			printf("The value of %d coins is %d cents.\n",quarter+dime+nickel+penny,x);
			printf("\n");
			printf(". . .\n");
			printf("\n");
		}
	}
	return 0;

}