min stack problem

[Praniksha123]

No description provided.

[super30admin]

Implement Hash Set (min stack problem)

1. Problem Mismatch: The student submitted a Min Stack solution instead of a HashSet implementation. This suggests either misunderstanding the problem or submitting the wrong code.

2. Correctness: The solution is incorrect for the given problem - it solves a different problem entirely.

3. What to do: The student needs to implement a HashSet using techniques like:

   • A boolean array (since keys are in range 0 to 10^6)
   • A hash function to map keys to array indices
   • Separate chaining or open addressing for collision handling
   • The reference solution uses a 2D boolean array with double hashing

4. Strengths in submitted code: The Min Stack implementation is well-structured with clear variable names and follows good practices for that problem.

5. Areas for improvement: The student needs to ensure they are solving the correct problem. For HashSet implementation, they should focus on:

   • Using appropriate hash functions
   • Handling the key range efficiently (0 to 10^6)
   • Implementing all three required methods correctly

VERDICT: NEEDS_IMPROVEMENT

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Implement Min Stack

Strengths:

• Clean, readable implementation that matches the optimal approach
• Correct use of auxiliary stack to track minimums
• Proper handling of min restoration after pop operations
• Good variable naming convention

Areas for Improvement:

• Could add comments to explain the algorithm logic, especially for the min stack tracking approach
• The min field is technically redundant since it's always equal to minst.peek() - could simplify by removing it and always reading from min stack
• Consider adding null checks or documentation about constraints

Overall, this is a solid implementation that correctly solves the problem with optimal time complexity.

VERDICT: PASS