I don't want the program for this. I want to understand this program for this class. It is a java program to simulate shopping and inventory. LinkedList is required to be used.

On some shopping sites (e.g., amazon.com), a product can have multiple sellers. Usually, the seller list is displayed based on

the total cost (product price plus shipping cost). The inventory of the product at a seller determines whether the seller is on

the seller list.

For this assignment, assume you are managing three products: appleIPhone, hdmi2VgaAdapter, and USBdrive. For

simplicity, the product price and shipping cost are set at the beginning and do not change. To separately manage the seller

list in ascending order of total cost for each product, use a singly linked list. Ties are broken by seller names in alphabetically

order. When the inventory is zero, the corresponding node, is deleted.

Data should be used in a file.

Input: To simulate the shopping and inventory events, an input file contains events in the same directory as your program

file called HW1.java that has the main method. Initially, each product has no sellers (no inventory). Your submission takes

the input file name as a command-line argument. Each line is one of the following event:

SetProductPrice product seller price

SetShippingCost seller shippingCost minimumForFreeShipping

IncreaseInventory product seller quantity

CustomerPurchase product seller quantity

DisplaySellerList product

Shipping cost is zero if the product price is at least minimumForFreeShipping. DisplaySellerList considers the cost of one

item of the product.

Output: The program prints events to the standard output (screen). Each event is on one line and possible events are:

SetProductPrice product seller price

SetShippingCost seller shippingCost minimumForFreeShipping

IncreaseInventory product seller quantity updatedInventory

CustomerPurchase product seller quantity updatedInventory or NotEnoughInventoryError

DepletedInventoryRemoveSeller product seller

DisplaySellerList product

12345678901234567890123456789012345678901234567890 // just to show spacing

seller productPrice shippingCost totalCost // output starts

walmart 20.99 0.00 20.99

amazon 16.95 5.00 21.95

bestbuy 21.99 0.00 21.99

Assume a seller's name is at most 10 characters, use right justification for each column in the seller list. When inventory is

depleted, DepletedInventoryRemoveSeller is displayed and the corresponding node is removed.

Sample Input 1:

SetProductPrice appleIPhone amazon 499 SetProductPrice appleIPhone applestore 550 SetProductPrice appleIPhone bestbuy 515 SetProductPrice appleIPhone walmart 450 SetShippingCost amazon 10 20 SetShippingCost applestore 15 50 SetShippingCost bestbuy 5 35 SetShippingCost walmart 10 10 IncreaseInventory appleIPhone amazon 10000 10000 IncreaseInventory appleIPhone applestore 500 500 CustomerPurchase appleIPhone amazon 1 9999 CustomerPurchase appleIPhone bestbuy 2 NotEnoughInventoryError CustomerPurchase appleIPhone applestore 5 495 DisplaySellerList

Sample Output 1:

 seller productPrice shippingCost totalCost walmart 450.00 0.00 450.00 amazon 499.00 0.00 499.00 bestbuy 515.00 0.00 515.00 applestore 550.00 0.00 550.00

Sample Input 2:

SetProductPrice USBdrive amazon 4.99 SetProductPrice AppleIphone applestore 1000 SetProductPrice USBdrive radioshack 5.99 SetProductPrice USBdrive bestbuy 3.99 SetProductPrice hdmi2VgaAdapter bestbuy 13.99 SetProductPrice USBdrive walmart 3.50 SetProductPrice hdmi2VgaAdapter walmart 12.50 SetShippingCost amazon 5 10 SetShippingCost applestore 15 50 SetShippingCost bestbuy 5 25 SetShippingCost walmart 10 5 SetShippingCost radioshack 10 5 IncreaseInventory USBdrive amazon 5000 5000 IncreaseInventory USBdrive bestbuy 500 500 IncreaseInventory USBdrive walmart 2500 2500 IncreaseInventory USBdrive radioshack 10 10 IncreaseInventory USBdrive amazon 5000 10000 IncreaseInventory AppleIphone applestore 100 100 IncreaseInventory hdmi2VgaAdapter bestbuy 100 100 IncreaseInventory hdmi2VgaAdapter walmart 1000 1000 DisplaySellerList USBdrive

Sample Output 2:

 seller productPrice shippingCost totalCost radioshack 5.99 0.00 5.99 bestbuy 3.99 5.00 8.99 amazon 4.99 5.00 9.99 walmart 3.50 10.00 13.50

Sample Output 2 but seller list is for another item (hdmi2VgaAdapter):

Sample Output 2 but seller list is for another item (AppleIphone):

Sample output 2 but edit to seller list and item (USBdrive):

This is the edit:

CustomerPurchase USBdrive radioshack 10 0 DepletedInventoryRemoveSeller USBdrive radioshack DisplaySellerList USBdrive

so this should be the output:

 seller productPrice shippingCost totalCost bestbuy 3.99 5.00 8.99 amazon 4.99 5.00 9.99 walmart 3.50 10.00 13.50