Ndtyjky

I'm attempting to write a program in which:

• The user inputs the cost of an item


• The user inputs the amount they paid for the item


• The program determines if the user is owed any change


• The program calculates the amount of change owed


• The program uses the modulus operator to break the amount of change down into coin denominations


• The program stores the change and coin denominations into an array This is the first bit at which I'm getting stuck
  


• The program displays the amount of change in coin denominations to the user

The purpose is to use an array to hold the values of the coins, so I "can write a general purpose change calculator that can be used for any coinage by changing the contents of the array".

Here is my code:

void vendingMachine()

{



    // Declarations

    #define ARRAY_LENGTH 6



    int itemCost;

    int amountEntered;

    int fifty, twenty, ten, five, two, one; 

    int remainder;



    // User input



    printf("Please enter the cost of the item in pence: ");

    scanf_s("%d", &itemCost);

    while (itemCost <= 0 || itemCost > 99)

    {

        printf("You've entered an invalid amount. Please enter an amount between 1p and 99p: ");

        scanf_s("%d", &itemCost);

    }



    printf("Please enter the amount entered into the machine in pence: ");

    scanf_s("%d", &amountEntered);

    while (amountEntered <= 0 || amountEntered > 100)

    {

        printf("You've entered an invalid amount. Please enter an amount between 1p and 100p: ");

        scanf_s("%d", &amountEntered);

    }



    while (amountEntered < itemCost)

    {

        printf("You've entered an invalid amount. Please enter an amount equal to or higher than the cost of the item: ");

        scanf_s("%d", &amountEntered);

    }



    // Program to determine if the customer is owed any change and, if so, how much is owed



    if (amountEntered == itemCost)

    {

        printf("No change is owed to the customer");

    }

    else if (amountEntered > itemCost)

    {

        int change = amountEntered - itemCost;

        printf("The amount of change owed to the customer is: %d pence, broken down as follows: n", change);



        fifty = change / 50;

        remainder = change % 50;

        twenty = remainder / 20;

        remainder = remainder % 20;

        ten = remainder / 10;

        remainder = remainder % 10;

        five = remainder / 5;

        remainder = remainder % 5;

        two = remainder / 2;

        remainder = remainder % 2;

        one = remainder;



         // Program to store the change in an array



        int count[ARRAY_LENGTH];

        count[0] = fifty;

        count[1] = twenty;

        count[2] = ten;

        count[3] = five;

        count[4] = two;

        count[5] = one;



        for (int i = 0; i < ARRAY_LENGTH; i++)

        {

             count[i] = 0;

        }



        for (int i = 0; i < ARRAY_LENGTH; i++)

        {

            printf("The number of %d coins is: %dn", //I don't know what to do here);

        }

    }

}

Store the type of coins in an array as well, e.g.

const int coins[ARRAY_LENGTH] = { 50, 20, 10, 5, 2, 1 };

Then you can easily refer to them in your loop:

printf("The number of %d coins is: %dn", coins[i], count[i]);

This also allows you to perform your modulo calculations in a loop.

I am not sure what you are trying to achieve here:

The following piece of (your) code sets the values of count from index 0 to index 5, starting from fifty to one..

int count[ARRAY_LENGTH];

count[0] = fifty;

count[1] = twenty;

count[2] = ten;

count[3] = five;

count[4] = two;

count[5] = one;

Then here, you are overwriting those with 0 in the for loop.

for (int i = 0; i < ARRAY_LENGTH; i++)

{

     count[i] = 0;

}

So above loop is not required, or at least must not be placed after you have assigned values of fifty, twenty, ten, five, two and one to count array indices.

I guess you are trying to print them? You don't have to use a loop here:

// Doing it the newbie-way:



printf("The number of coins of 50 are: %dn", count[0]);

printf("The number of coins of 20 are: %dn", count[1]);

printf("The number of coins of 10 are: %dn", count[2]);

printf("The number of coins of 5 are: %dn", count[3]);

printf("The number of coins of 2 are: %dn", count[4]);

printf("The number of coins of 1 are: %dn", count[5]);