Inventory Management System

This problem involves managing a simple inventory system. You need to implement operations to add, update, delete, check stock, and display inventory items. Each product is identified by a unique product ID.

Operations are defined as follows:

• ADD: Add a new product or update an existing product using the command format: ADD product_id name quantity price.
• UPDATE_QUANTITY: Update the quantity of a product: UPDATE_QUANTITY product_id quantity.
• UPDATE_PRICE: Update the price of a product: UPDATE_PRICE product_id price.
• DELETE: Remove a product from the inventory: DELETE product_id.
• CHECK_STOCK: Check the stock quantity of a product: CHECK_STOCK product_id. If the product does not exist, output None.
• DISPLAY: Display all products in ascending order by product ID. Each product is printed in the format: product_id name quantity price.

You can view the inventory mathematically as follows:

$$\text{Inventory}(pid)=\{\text{name},\,\text{quantity},\,\text{price}\}$$

inputFormat

The first line contains an integer n representing the number of commands. Each of the following n lines contains a command in one of the following formats:

• ADD product_id name quantity price
• UPDATE_QUANTITY product_id quantity
• UPDATE_PRICE product_id price
• DELETE product_id
• CHECK_STOCK product_id
• DISPLAY

outputFormat

For each CHECK_STOCK and DISPLAY command, output the result on a new line. For CHECK_STOCK, output the quantity if the product exists, or None if it does not. For DISPLAY, output each product's details on a new line in the format: product_id name quantity price.

6
ADD 101 Apple 50 30
CHECK_STOCK 101
DISPLAY
UPDATE_QUANTITY 101 60
UPDATE_PRICE 101 35
DISPLAY

50
101 Apple 50 30
101 Apple 60 35