Minimum Consecutive Cards to Pick Up

You are given an integer array cards where cards[i] represents the value of the ith card. A pair of cards are matching if the cards have the same value.

Return the minimum number of consecutive cards you have to pick up to have a pair of matching cards among the picked cards. If it is impossible to have matching cards, return -1.

Example 1:

Input: cards = [3,4,2,3,4,7]
Output: 4
Explanation: We can pick up the cards [3,4,2,3] which contain a matching pair of cards with value 3. Note that picking up the cards [4,2,3,4] is also optimal.

Example 2:

Input: cards = [1,0,5,3]
Output: -1
Explanation: There is no way to pick up a set of consecutive cards that contain a pair of matching cards.

Constraints:

• 1 <= cards.length <= 105
• 0 <= cards[i] <= 106

SOLUTION:

class Solution:
    def minimumCardPickup(self, cards: List[int]) -> int:
        n = len(cards)
        pos = {}
        minDiff = float('inf')
        for i in range(n):
            if cards[i] in pos:
                minDiff = min(minDiff, i - pos[cards[i]] + 1)
            pos[cards[i]] = i
        if minDiff == float('inf'):
            return -1
        return minDiff