Completed Pre course 1

[sanjoli97]

No description provided.

[super30admin]

Exercise_1.java (Array-based Stack):

• Strengths: Clean implementation with proper encapsulation. The push/pop/peek operations are O(1) as expected. Good use of comments explaining time/space complexity. Proper overflow/underflow handling.
• Areas for Improvement: The pop() method returns 0 on underflow, which is problematic since 0 could be a valid stack value. Should throw an exception or use a different sentinel value. The a = new int[MAX] in the constructor is redundant since the array is already initialized at declaration.
• Edge Cases: Not handling null checks or invalid inputs explicitly.

Exercise_2.java (Linked List-based Stack):

• Strengths: Good O(1) operations for push/pop/peek. Clean node structure. Proper handling of empty stack case.
• Areas for Improvement: Same issue as Exercise_1 - returning 0 on underflow/empty peek is ambiguous. The push method could return boolean for consistency with typical stack interfaces.
• Edge Cases: No explicit error handling or exceptions thrown.

Exercise_3.java (Linked List Implementation):

• Strengths: Good basic linked list implementation. Clean structure with separate Node inner class. Proper traversal logic.
• Areas for Improvement: The insert method has O(n) time complexity for each insertion (traversing to end), making overall insertion O(n²). Could be optimized using a tail pointer. The method returns the list but doesn't need to since list reference doesn't change. No deletion or search methods implemented.
• Edge Cases: No validation for null data or empty list handling in printList.

General Observations:

• All three implementations compile and run correctly for basic use cases
• Good practice of including time/space complexity comments
• Could benefit from generic types instead of just int
• No JUnit tests or edge case testing shown
• Code formatting is consistent and readable