solution to both problems

[avishwak]

No description provided.

[super30admin]

1. Correctness:

   • HashSet: The implementation correctly uses a 2D list with two hash functions to handle collisions. The special case for bucket 0 is handled well to accommodate the maximum key value (10^6). The operations (add, remove, contains) appear to be correctly implemented.
   • MinStack: The solution correctly uses two stacks to maintain the minimum value efficiently. The push, pop, top, and getMin operations are correctly implemented with O(1) time complexity.

2. Time Complexity:

   • HashSet: The time complexity for add, remove, and contains operations is O(1), as claimed. This is correct due to the use of hash functions and direct array access.
   • MinStack: The time complexity for push, pop, top, and getMin operations is O(1), as claimed. This is correct because stack operations are inherently O(1).

3. Space Complexity:

   • HashSet: The space complexity is O(n), where n is the number of unique keys. This is correct because the storage grows with the number of keys.
   • MinStack: The space complexity is O(n), where n is the number of elements in the stack. This is correct because both stacks grow linearly with the number of elements.

4. Code Quality:

   • HashSet: The code is well-structured and readable. The use of helper functions (hash1 and hash2) improves readability. Comments are clear and explain the approach well.
   • MinStack: The code is clean and easy to follow. The use of a separate min stack is a good approach. The comments are helpful, but the initialization of Min could be more explicit (e.g., float('inf') instead of sys.maxsize).

5. Efficiency:

   • HashSet: The solution is efficient, but there is a minor inefficiency in the remove method where it checks if self.storage[bucket] == None but still proceeds to set the value to False. This could be optimized by returning early if the bucket is None.
   • MinStack: The solution is efficient, but the minSt stack could be optimized further by only pushing to it when the new value is less than or equal to the current minimum, which is already implemented correctly.

Areas for Improvement:

• HashSet: Consider adding a check in the remove method to return early if the bucket is None, as setting False on a None bucket would raise an error (though the current implementation avoids this by checking None before accessing).
• MinStack: The initialization of Min could be more explicit (e.g., float('inf')) to make it clearer. Also, consider adding a check for empty stack in top and getMin to handle edge cases gracefully.