The ACME Company has approached you with a request to develop the psuedocode that will control the operations of their new series of vending machines. The program will be required to maintain the product inventory and money reservoir. The program should do the following operations:

Question

1. Take as input an item number and money (The program terminates when a user enters a negative money amount and “000” as an item number.)

2. Check to see if the item exists. (if it doesn’t give the user a chance to re-enter the number)

3. Check to see if the money is sufficient enough to pay for item. (If not request more money)

4. Check to see if item is in stock. (If not user should be notified with the choice of selecting new item or cancelling the order)

5. If the item is in stock and the money is sufficient, the program should provide change and update the money reservoir and product inventory.

6. When the dispensing change, the program must insure that it always returns the correct amount of change based on the coins available in the reservoir. For example, if a user is owed $0.30 then the program may return 1 quarter and 1 nickel. However, if there are no quarters, the program should be smart enough to return a different combination of that doesn’t include quarters. (If no combination of change exists, the user’s order should be cancelled and the user should be allowed to make an alternate selection)

7. Once a transaction is complete, the user should be prompted to make a new selection. The program will end when a user enters a negative money amount and “000” for the item number.

Product Inventory:

Below is a breakdown of the products offered by the vending machine. In addition to the product names, the prices, item number and quantities are also listed below. The user will use the item number to select the product they wish to purchase.

Product Name Item Number Price Quantity in Stock

Candy Bar 123 $0.60 60

Gum 124 $0.35 75

Potato Chips 125 $0.75 40

Trail Mix 126 $.050 50

Breakfast Bar 127 $0.80 45

Answer 1

Here is the pseudocode for controlling the operations of the vending machine:

1. Initialize the money reservoir and product inventory.

2. Display a message to the user to enter an item number and money.
2.1. Read the item number and money from the user.
2.2. If the money is negative and the item number is "000", terminate the program.

3. Check if the item number exists in the product inventory.
3.1. If the item number doesn't exist, display an error message and go back to step 2.

4. Check if the money is sufficient to pay for the item.
4.1. If the money is less than the price of the selected item, display an error message and go back to step 2.

5. Check if the selected item is in stock.
5.1. If the quantity of the selected item is zero, display a message asking the user to select a new item or cancel the order.
5.2. If the user chooses to cancel the order, go back to step 2.
5.3. If the user chooses to select a new item, prompt the user to enter a new item number and go back to step 2.

6. Calculate the change to be given to the user.
6.1. Subtract the price of the item from the entered money to get the change.
6.2. Set the current change value to the calculated change.
6.3. Initialize variables for counting the number of each coin.
6.4. While the current change is greater than zero, do the following:
6.4.1. If the current change is greater than or equal to the value of a quarter and the quantity of quarters in the money reservoir is greater than zero, subtract a quarter from the current change and decrement the quantity of quarters.
6.4.2. If the current change is greater than or equal to the value of a dime and the quantity of dimes in the money reservoir is greater than zero, subtract a dime from the current change and decrement the quantity of dimes.
6.4.3. If the current change is greater than or equal to the value of a nickel and the quantity of nickels in the money reservoir is greater than zero, subtract a nickel from the current change and decrement the quantity of nickels.
6.4.4. If the current change is greater than or equal to the value of a penny and the quantity of pennies in the money reservoir is greater than zero, subtract a penny from the current change and decrement the quantity of pennies.
6.4.5. If none of the available coins can be used to make change, the user's order should be cancelled. Display a message indicating that change cannot be given and go back to step 2.

7. Update the money reservoir and product inventory.
7.1. Subtract the quantity of the selected item from the product inventory.
7.2. Add the entered money to the money reservoir.

8. Display a message to the user indicating the successful transaction and the change given.
8.1. Display the item name, price, and the change given.

9. Prompt the user to make a new selection and go back to step 2.