Problem1 and Problem3

[megharaykar]

No description provided.

[super30admin]

Strengths:

• The student provided multiple solutions (iterative and recursive) for the problem, showing a comprehensive understanding.
• The code is well-commented and structured.
• The iterative solution is efficient with O(1) space.

Areas for improvement:

1. Time Complexity Comment: In the iterative solution, the comment says "Time Complexity: O(2n)". This is misleading because the loop runs exactly n times, not 2n. Please correct it to O(n).
2. Variable Naming: In the recursive solution without helper, the variable 're' should be renamed to something more descriptive, like 'reversed_head' or 'new_head'.
3. Recursive Helper Solution: The recursive solution using a helper function and a class variable is not ideal. Class variables can lead to issues if the same Solution instance is used multiple times. Instead, consider implementing the recursive helper without a class variable. For example, you can return the new head from the helper function.
4. Extra Problem: The solution for "Linked List Cycle II" (Problem3.py) is included in the submission, but the problem only asks for reversing a linked list. Please ensure that you only submit the code for the requested problem.

Suggested improvement for the recursive helper solution:

class Solution:
    def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
        if head is None:
            return None
        return self.helper(head)
    
    def helper(self, node):
        if node.next is None:
            return node
        new_head = self.helper(node.next)
        node.next.next = node
        node.next = None
        return new_head

However, note that this helper function is similar to the direct recursive solution. Alternatively, you can avoid the helper function altogether.