Medium

Minimum Consecutive Cards to Pick Up

LAB

Return the length of the shortest contiguous subarray containing a repeated card value, or -1 if none exists.

EXAMPLES

Example 1

Input
{
  "cards": [
    3,
    4,
    2,
    3,
    4,
    7
  ]
}

Output
4

FUNCTION SHAPE

cards: intArray→int

SOLUTION NOTE

Straightforward min template. We are valid once we have a repeating card (freq == 2).

Reveal reference solution +

pythonREFERENCE

def minimumCardPickup(self, cards: List[int]) -> int:
    n, l, freq, res = len(cards), 0, Counter(), float('inf')

    for r in range(n):
        freq[cards[r]] += 1

        while freq[cards[r]] == 2:
            res = min(res, r - l + 1)
            freq[cards[l]] -= 1
            l += 1

    return res if res != float('inf') else -1

TimeO(n)

SpaceO(n)

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