Maximize products bought under budget

A store carries N distinct products. Each product has an integer product_id and a non-negative integer price. There are M customers, each with an integer customer_id and a non-negative integer budget. For each customer, choose a subset of distinct products whose total price does not exceed that customer's budget. The customer may select at most one copy of each product. The primary objective is to maximize the number of selected products. Among subsets with the same maximum…