Precourse 1 completed

[thondaha]

Precourse 1 ccompleted

[super30admin]

The student's solution demonstrates a good understanding of implementing basic data structures in Java. Here's a detailed evaluation:

1. Correctness:

• The Stack implementation using an array (Exercise_1.java) correctly handles push, pop, peek, and isEmpty operations with proper overflow/underflow checks.
• The LinkedList implementation (LinkedList.java) correctly handles insertion and printing of nodes.
• The StackAsLinkedList implementation (StackAsLinkedList.java) correctly implements stack operations using linked nodes.

2. Time Complexity:

• For Stack (array implementation): All operations (push, pop, peek, isEmpty) are O(1) as expected.
• For LinkedList: Insertion is O(n) due to traversal to the end, which is correct for this implementation.
• For StackAsLinkedList: All operations are O(1) as expected.

3. Space Complexity:

• All implementations have appropriate space complexity (O(n) where n is number of elements).

4. Code Quality:

• The code is generally well-structured and readable.
• Good use of comments explaining the operations.
• Consistent indentation and formatting.
• Could improve by adding class-level comments explaining the purpose and complexity.

5. Efficiency:

• The implementations are efficient for their respective data structures.
• One minor optimization could be to make the MAX constant in Stack.java final (it's already effectively final but could be explicitly declared).

Areas for Improvement:

• Missing time/space complexity comments at the top of each file as requested in the problem statement.
• Could add more edge case testing (e.g., testing empty stack operations more thoroughly).
• The LinkedList implementation could benefit from a tail pointer to make append operations O(1).
• Some redundant code in error handling (e.g., "Stack Underflow" message appears in multiple places).