The problem statement they give you is basically nothing.
Clarify the rules (tile ranks, meld definitions, and whether suits matter) and then design a recursive backtracking algorithm that tries all possible pairs and melds. Explain the algorithm, analyze its complexity, and discuss potential optimizations like memoization or pruning.
Pro tip: Demonstrate strong problem-solving by first handling the edge case of invalid tile counts (e.g., total tiles not 14) and then discussing how to adapt the solution if the rules change (e.g., multiple suits or additional meld types).
Ask about tile representation (e.g., integers 1-9 for ranks, possibly suits), meld definitions (triplet = three identical, run = three consecutive), and winning condition (one pair + four melds). Confirm that the hand has exactly 14 tiles.
Propose a recursive backtracking approach: try each possible pair, then recursively attempt to form four melds from the remaining tiles. Alternatively, use dynamic programming or memoization to avoid redundant checks.
Write pseudocode for the backtracking function, ensuring it handles tile counts correctly. Test with edge cases: winning hand, near-winning hand, invalid tile counts, and hands with multiple possible pairs.
Discuss time complexity (e.g., O(n^2) or exponential in worst case) and space complexity. Suggest optimizations like sorting tiles, using a frequency map, and pruning branches early.
Compare backtracking with other approaches (e.g., greedy, DP) and explain why backtracking is suitable. Mention how to extend the solution for multiple suits or additional meld types.
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