Leetcode - Flatten a Multilevel Doubly Linked List (Python)

July 2020 Leetcode Challenge
Leetcode - Flatten a Multilevel Doubly Linked List

[nandhakiran]

Thank you very much for this. I was doing this with recursion and even though I was positive the logic was correct I kept getting "not a valid doubly linked list". After struggling for 10-15 mins I decided to check out your video and turns out I forgot to assign None to the child after flattening each node. LMAO, I feel really dumb.

[sangwonsong]

Thanks for great explanation. I learned some intuitive ideas for this type of problem.

[asynciz]

"And remember, do not trust me, I know nothing." :D