Abhishek_Chaudhari

[chaudhari-ab]

This is the pull request for 3 Precourse exercises from Abhishek Chaudhari.
Kindly review.

[super30admin]

The student's solution demonstrates a good understanding of basic data structures like stacks and linked lists. Here's a detailed evaluation:

1. Exercise_1.java (Array-based Stack):

• Correctness: The implementation has a logical error in the push() method where it checks if(top<0) first, which will always prevent pushing elements onto an empty stack. This should be removed.
• Time Complexity: Correctly identified as O(1) for all operations.
• Space Complexity: Correctly identified as O(MAX).
• Code Quality: Well-structured but needs better error handling (returning 0 for errors isn't ideal).
• Efficiency: The array-based approach is efficient but the implementation needs fixing.

2. Exercise_2.java (Linked List-based Stack):

• Correctness: Correct implementation of stack operations using linked list.
• Time Complexity: Correctly identified as O(1) for all operations.
• Space Complexity: Correctly identified as O(n).
• Code Quality: Clean and well-structured. Good use of OOP principles.
• Efficiency: Efficient implementation with no obvious improvements needed.

3. Exercise_3.java (Linked List):

• Correctness: Correct implementation of linked list insertion and printing.
• Time Complexity: Insertion is O(n) due to traversal to the end, but not mentioned in comments.
• Space Complexity: Correct at O(n) but not explicitly stated for the LinkedList class.
• Code Quality: Good structure but could benefit from more methods (e.g., delete).
• Efficiency: Standard implementation, though maintaining a tail pointer could make insertions O(1).

General Improvements Needed:

1. Error handling could be improved (consider throwing exceptions instead of returning 0).
2. Comments should be more consistent and detailed.
3. The push() method in Exercise_1.java needs correction.
4. Time complexity analysis should be more complete (especially for Exercise_3.java).

[chaudhari-ab]

Chnages in revision -

1. Fixed push() method in Exercise_1.java
2. Added Error handling instead of returning 0
3. Addressed the time complexity in Exercise_3.java