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Randomly Shuffle a Deck

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Your question is Randomly Shuffle a Deck. Start with the requirements on the right.

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Problem

Uline may use randomized card decks for testing warehouse picking workflows. Given a list representing a deck, return a uniformly random permutation of the cards without modifying the original list.

Implement shuffle_deck(deck, seed). The optional seed makes the result deterministic for testing. When seed is None, use system-provided randomness. Every permutation must have equal probability.

Formal Specification

  • Input: deck, a Python list containing distinct or repeated card values, and seed, an integer or None.
  • Output: A new Python list containing exactly the same values as deck, possibly in a different order.
  • The input list must remain unchanged.
  • Use the Fisher-Yates algorithm rather than repeatedly selecting and removing random elements.

Constraints

  • 0 <= len(deck) <= 10^5
  • Card values may be any Python values that can be stored in a list
  • The input list must not be modified
  • The output must preserve every input value and its multiplicity

Function Signature

def shuffle_deck(deck, seed):
Your solutionPython 3
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