PayPal OA - Java backend engineer

Round 1

Questions:

1. Items Purchase
   n items where the price of the ith item is price[i]. A frequent customer has m discount coupons. If x discount coupons are used on the ith item, its price is reduced to the integer floor(price[i] / 2^x), e.g. floor(3/2^1) = floor(1.5) = 1.
   Find the minimum amount needed to purchase all the items of the shop using at most m coupons.

   Example: Consider n = 2, price = [2, 4], m = 2. The optimum solution:

   • Purchase item 1 for 2.
   • Use 2 coupons on item 2, so the discounted price is 4/2^2 = 4 / 4 = 1.
     The amount required = 2 + 1 = 3.

   Function Description: Complete the function findMinimumPrice in the editor below.
   findMinimumPrice has the following parameters:

   • int price[n]: the original prices of the items
   • int m: the number of discount coupons

   Constraints:

   • 1 <= n <= 10^5
   • 0 <= m <= 10^9
   • 1 <= price[i] <= 10^9

2. Java Specific Question
   Create and implement Product class.
   Implement the classes shown:

   • Create a class called Product that implements the /Product interface.
   • This class should have the following properties:
     • String productid
     • int salesVelocity
     • int stockLevel
   • Implement the constructor Product(String productid, int salesVelocity, int stockLevel)
   • Create a class called InventoryClearance.
   • Create a method called identifyClearanceItems(List<Product> products) that returns a list of strings representing the product IDs that are eligible for clearance.

   Constraints:

   • 1 <= n <= 10^5
   • 0 <= salesVelocity <= 10^5
   • 0 <= stockLevel <= 10^5