Book Combinations

You have store credit of $N$ dollars. However, you don’t want to walk a long distance with heavy books, but you want to spend all of your store credit.

Let’s say we have a list of books in the format of tuples where the first value is the price and the second value is the weight of the book -> (price,weight).

Write a function optimal_books to retrieve the combination that allows you to spend all of your store credit while getting at least two books at the lowest weight.

Note: You should spend all your credit and getting at least 2 books, If no such condition is satisfied just return empty list.

Example:

Input:

N = 18
books = [(17,8), (9,4), (18,5), (11,9), (1,2), (13,7), (7,5), (3,6), (10,8)]

def optimal_books(N, books) -> [(17,8),(1,2)]