Completed PRECOURSE-1

[aditya-bandaru-06]

No description provided.

[super30admin]

Let me evaluate each exercise separately:

Exercise_1.py (Stack implementation using list):

• Correctness: The implementation correctly follows stack operations (LIFO) using Python list. All methods work as expected.
• Time Complexity:
  • push(), pop(), peek(), isEmpty(), size() are all O(1)
  • show() is O(n) since it returns the entire list
• Space Complexity: O(n) where n is number of elements in stack
• Code Quality: Clean and readable. Good use of list methods. Could add docstrings.
• Improvement: Consider returning empty list instead of None for peek() when empty.

Exercise_2.py (Stack using linked list):

• Correctness: Correctly implements stack using linked list. Handles empty stack case.
• Time Complexity: push() and pop() are O(1)
• Space Complexity: O(n) where n is number of elements
• Code Quality: Good structure. The dummy head node (-1) is unnecessary - could just use None.
• Improvement: Could add isEmpty(), peek(), size() methods for completeness.

Exercise_3.py (Singly linked list):

• Correctness: Correctly implements append, find and remove operations.
• Time Complexity:
  • append(): O(n)
  • find(): O(n)
  • remove(): O(n)
• Space Complexity: O(n)
• Code Quality: Well-structured. Good use of ListNode class. Docstrings are present.
• Improvement: Could add str method for debugging. Remove could return success/failure.

General strengths:

• All implementations are functionally correct
• Good understanding of data structures
• Proper handling of edge cases (empty stacks/lists)
• Clean code formatting

Areas for improvement:

• Add more documentation (docstrings)
• Consider more complete interfaces (all common operations)
• For linked list, consider tail pointer to make append O(1)
• Add more test cases in the code