2611 Mice and Cheese

Mouse 1 can eat k types of cheese. Mouse 2 can eat all of them. Cheese at index i can only be eaten by one of the two mice at a time.

That means, if mouse 1 eats rewards1[2], mouse 2 cannot eat cheese at index 2.

Since our goal is maximising - mouse 1 should eat the top k rewarding cheeses, and the remaining ones are automatically eaten by mouse 2.

Code

Python3

def miceAndCheese(self, reward1: List[int], reward2: List[int], k: int) -> int:
    if k == 0: return sum(reward2)
    
    indices = set(
        i for _, i in sorted(
            ((a - b, i) for i, (a, b) in enumerate(zip(reward1, reward2))),
            key=lambda x: x[0],
        )[-k:]
    )
    return sum(
        (a if i in indices else b) for i, (a, b) in enumerate(zip(reward1, reward2))
    )

Big O Analysis

• Runtime

  The runtime complexity here is $O(N)$ since we are using functions like enumerate, zip, and sum.

• Memory

  The memory usage is $O(N)$ since we create lists with functions like enumerate, and zip. Also, set().

— A

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