#822

Card Flipping Game

specialist · 935 · lc medium +32 · verified · 50% accepted · 192 likes · top 38%

Description

You have n cards arranged in a row, each with a positive integer printed on its front (fronts[i]) and back (backs[i]). Initially every card shows its front face up. You may flip any subset of cards.

After flipping, an integer is considered good if it appears face-down on at least one card and does not appear face-up on any card.

Return the smallest good integer that can be achieved. If no good integer exists, return 0.

Example 1:

Input: fronts = [1,2,4,4,7], backs = [1,3,4,1,3]

Output: 2

Explanation:

If we flip the second card, the face up numbers are [1,3,4,4,7] and the face down are [1,2,4,1,3].

2 is the minimum good integer as it appears facing down but not facing up.

It can be shown that 2 is the minimum possible good integer obtainable after flipping some cards.

Example 2:

Input: fronts = [1], backs = [1]

Output: 0

Explanation:

There are no good integers no matter how we flip the cards, so we return 0.

Code

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class Solution:
    def flipgame(self, fronts: List[int], backs: List[int]) -> int:

class Solution:
    def flipgame(self, fronts: List[int], backs: List[int]) -> int: