My first instinct was to just throw everything into a list and simulate naively, which works until you realize cycles are a real problem.
Model the game as a state machine where each state is defined by the current hands of both players. Simulate rounds using queues for efficient card drawing and handle ties by drawing up to three additional cards. Use a hash set to detect repeated states and terminate early, returning the winner and round count.
Pro tip: Clarify the tie-breaking rules upfront (e.g., if a player runs out of cards during a tie, they lose immediately) and discuss the trade-offs between using a hash set for state detection versus other methods like cycle detection with Floyd's algorithm.
Ask about tie resolution specifics, what happens if a player cannot draw enough cards during a tie, and how to handle empty queues. Confirm the definition of a repeated state (e.g., same card sequences in both hands).
Use queues (e.g., deque) for each player's hand to efficiently draw from the front and add to the back. Use a hash set to store serialized states (e.g., tuple of both queues) for cycle detection.
In each round, draw one card from each player. Compare ranks; if different, higher card wins and both cards go to the winner's queue in a specific order. If tie, draw up to three additional cards from each player, compare the last drawn cards, and distribute all drawn cards accordingly.
After each round, serialize the current state and check if it has been seen before. If so, declare a draw and return the round count. Also handle termination when a player runs out of cards.
Return the winner (player 1, player 2, or draw) and total rounds. Discuss time and space complexity, noting that state space is finite but can be large, and the hash set prevents infinite loops.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.