Compute Max Score From Up to 3 Categories

You are implementing a scoring function for a library summer reading program.

Each book a student read is represented as a tuple (category: str, points: int).

Rules:

• The student may count points from at most 3 books .
• Any counted books must be from distinct categories (i.e., you can pick at most one book per category ).
• The student may pick fewer than 3 books if fewer categories exist.

Task: Implement the function:

from typing import List, Tuple

def get_max_score(books: List[Tuple[str, int]]) -> int:
    """Return the maximum total points achievable under the rules."""

Examples:

test1 = [
    ("Adventure", 5),
    ("Adventure", 2),
    ("History", 3),
]
# Pick Adventure(5) + History(3) = 8
assert get_max_score(test1) == 8

test2 = [
    ("Adventure", 4),
    ("History", 3),
    ("Reference", 1),
    ("Fiction", 2),
]
# Pick top 3 categories: 4 + 3 + 2 = 9
assert get_max_score(test2) == 9

test3 = [
    ("Biography", 2),
    ("Biography", 4),
    ("Science", 3),
    ("Science", 1),
]
# Pick Biography(4) + Science(3) = 7
assert get_max_score(test3) == 7

test4 = []
assert get_max_score(test4) == 0

Constraints: assume len(books) can be large, so your solution should be efficient (better than trying all combinations).