Validate Binary Tree Nodes - Leetcode 1361 - Python

[@atharvapatil4247]

Was waiting for this solution today

[@ngneerin]

Same can be done with stack to reduce memory

[@amoghsv557]

Was waiting for this from 6 hours haha

[@zerocode-v9w]

Thank you brother

[@ratnadeepsaha7675]

Thank you for this video

[@akhilchauhan9417]

Can you do it with DSU? I am stuck at 42/44.
Failed Test Case:
n = 3
[1, -1, -1]
[-1, -1, 1]
I am checking for connected components == 1 plus no cycles. What am I missing??

[@Kan-JenLiu]

there are 2 root nodes, which is not a valid binary tree (has only 1 root node)

[@ngneerin]

Length of all unique nodes is 1 which is not equal to n-1. Should do this check right after making a list of unique nodes. And if fails return false even before doing anything else

[@akhilchauhan9417]

got it just made a ChildToPar hasmap for checking that

[@ngneerin]

@@akhilchauhan9417 use set instead

[@Romany_M]

how we can improve the space?

[@SohilGrandhi]

Thankyou❤

[@prasadm3614]

Love