Completed PreCourse-1

[Manassa2000]

No description provided.

[super30admin]

The student's solutions demonstrate a good understanding of basic data structures (stack and linked list) and their implementations. Here's a detailed evaluation for each file:

Exercise_1.java (Array-based Stack):

• Correctness: The implementation correctly handles stack operations (push, pop, peek) with proper checks for overflow/underflow.
• Time Complexity: Correctly identified as O(1) for all operations.
• Space Complexity: Correctly identified as O(MAX).
• Code Quality: Well-structured with clear comments. The isEmpty() method could be simplified to just return top == -1;.
• Edge Cases: Handles stack overflow and underflow correctly. One minor issue: System.err.println() is used for underflow message which might not be ideal for all scenarios.

Exercise_2.java (Linked List-based Stack):

• Correctness: Properly implements stack operations using linked list nodes.
• Time Complexity: Correctly identified as O(1) for all operations.
• Space Complexity: Correctly identified as O(n).
• Code Quality: Good structure, though "Stack UNderflow" has inconsistent capitalization. The peek() method should check for empty stack before accessing root.data.
• Edge Cases: Missing null check in peek() could cause NullPointerException.

Exercise_3.java (Linked List Implementation):

• Correctness: Correctly implements linked list insertion and printing.
• Time Complexity: Correctly identified as O(n) for insert and print operations.
• Space Complexity: Correctly identified as O(n).
• Code Quality: Well-structured with good separation of concerns. The insert method could be optimized by maintaining a tail pointer.
• Edge Cases: Handles empty list case correctly. The insert method could be made more efficient for large lists.

General Suggestions:

1. Add more comments explaining the logic in complex parts.
2. Consider using more descriptive variable names (e.g., 'last_node' could be 'current').
3. Add input validation where applicable.
4. For Exercise_2, consider throwing exceptions instead of returning 0 for stack underflow.
5. Consider adding Javadoc comments for public methods.