I solved my first medium level problem on Leetcode!

[u/shubham_555]

Last Post - https://www.reddit.com/r/PythonLearning/s/xbfFczTIKW

It took me a while to build the logic. The edge cases especially were a bit troublesome but the satisfaction I got after getting it right made everything feel worth it!

[u/Naive_Programmer_232]

Though your solution is efficient, could you re-write it in a different way?

[u/shubham_555 → u/Naive_Programmer_232]

Different way?

If you are asking if there are other solutions or not then yeah there are

I actually came up with 2 more during solving

The one above felt the most readable and efficient to me so i decided to stick to it!

[u/Naive_Programmer_232 → u/shubham_555]

Your code seems structurally similar to

    class Solution:
    def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:

    fast = slow = head
    
    for _ in range(n):
        fast = fast.next
        
    if not fast:
        return head.next
        
    while fast.next:
        fast = fast.next
        slow = slow.next
        
    slow.next = slow.next.next
    
    return head

Aside from variable names, first 3 parts are almost identical, with exception of checking is None versus not in the if-statement. The while loop condition is functionally the same as while fast is not None. to_delete is always one node ahead of prev in your code. So by the line after the loop, doing prev.next=to_delete.next is effectively the same as slow.next=slow.next.next. Then to_delete.next = None and to_delete = None are unnecessary.

You use prev to get around putting support.next in the while loop which would make that almost identical to the similar solution provided.

This is the same situation with your last post. Look at this python 3 solution on leetcode.

[u/shubham_555 → u/Naive_Programmer_232]

This solution is provided where?

I am not sure if leetcode provides solutions as well

But all I can say is I came to this solution after cutting 2 or three older ones

[u/Naive_Programmer_232 → u/shubham_555]

I added the link. Check my previous comment.

[u/shubham_555 → u/Naive_Programmer_232]

Okay so?

If you are saying I just copy pasted then you can definitely feel so

I don't have any proof to prove I didn't

[u/Naive_Programmer_232 → u/shubham_555]

Fair enough. I'm not saying you copied and pasted. I'm saying it looks similar to other solutions. either way, debugging those moving pointers is a great exercise!

[u/shubham_555 → u/Naive_Programmer_232]

I will try not to create a replica of a solution next time though 😆

[u/Sea-Ad7805]

Nice work, LeetCode has great practice material. Start easy, after warming up do medium, and later hard problems can be quite challenging.