Complete Array-1 assignment

[tejbharath]

No description provided.

[super30admin]

Product of Array Except Self (ProductOfArrayExceptSelf.java)

Great work! Your solution correctly implements the prefix/suffix product approach, which is the optimal O(n) time solution for this problem. The code is well-structured, readable, and includes helpful comments.

Strengths:

1. Correct O(n) time complexity, significantly better than the reference solution's O(n²).
2. Clear variable naming and good code organization.
3. Proper handling of edge cases (null/empty array).
4. Good comments explaining the approach.

Areas for improvement:

1. Space optimization (Follow-up): The problem's follow-up asks for O(1) extra space. You can achieve this by using the result array to store lProduct values, then doing a single right-to-left pass with a running product variable to compute the final result in-place. This would reduce space from O(n) to O(1).
2. Input modification: Your solution modifies the input array nums to store the result. While this works, it's generally better practice to create a new array for the output to avoid side effects on the input.
3. Comment accuracy: The comment "Add right product * left product in original array" should say "Multiply" instead of "Add".

VERDICT: PASS

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Diagonal Traverse (TraverseDiagonal)

Great work! Your solution correctly implements the diagonal traversal algorithm with the same approach as the reference solution. Here are some observations:

Strengths:

1. Correct Logic: The direction handling and boundary checks are correctly implemented
2. Good Comments: Your inline comments help explain the logic, especially the boundary conditions
3. Clean Structure: The code is well-organized and readable
4. Optimal Complexity: O(m*n) time and O(1) auxiliary space matches the optimal solution

Areas for Improvement:

1. Use of this.result: Using an instance variable for result is unnecessary. You could declare it as a local variable inside the method for better encapsulation and to avoid potential issues in concurrent environments.
2. Redundant Validation: The check if(mat == null || mat.length == 0) is somewhat redundant given the problem constraints (m, n >= 1). However, defensive programming is generally a good practice.
3. Variable Naming: Consider using more descriptive variable names like currentRow and currentCol instead of row and col for better readability.
4. Magic Numbers: The m*n is used multiple times - you could store it in a variable like totalElements for clarity.

VERDICT: PASS

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Spiral Matrix (SpiralMatrix)

Strengths:

1. Your solution correctly implements the spiral matrix traversal using the boundary-based approach.
2. The code is well-structured with clear comments explaining each step of the traversal.
3. You included proper input validation at the beginning.
4. The time and space complexity match the optimal solution.
5. The use of conditional checks (if(top <= bottom) and if(left <= right)) before traversing the bottom and left sides correctly handles edge cases like single rows or columns.

Areas for Improvement:

1. Minor code style: Consider adding a space after if keywords for consistency: if (top <= bottom) instead of if(top <= bottom).
2. Edge case consideration: While your solution handles the cases correctly, you could add a brief comment explaining why the conditional checks are necessary (they prevent double-counting elements in single-row or single-column matrices).
3. Variable naming: Your variable names are clear and consistent with the reference solution, which is good.

Overall, your solution is correct, efficient, and well-implemented. It demonstrates a solid understanding of the boundary-based spiral traversal technique.

VERDICT: PASS