Subtree of Another Tree - Leetcode 572 - Trees (Python)

[@GregHogg]

Master Data Structures & Algorithms For FREE at AlgoMap.io!

[@christianjt7018]

Great solution! I suggest a minor optimization: check the subtree only if the node and the head of the subroot have the same value.

[@franciscoserra8455]

I tested that out and the difference was minus 4 ms on average, so that's really really really a minor optimization that I would disregard in order to prioritize code readability :)

[@JoeTan-nq4fq]

Can further optimise by using stack (instead of recursion). stack = [root] while stack: node = stack.pop() # Initiate comparison if root nodes are the same if node.val == subRoot.val and isSameTree(node, subRoot): return True # Append child nodes if exist if node.right: stack.append(node.right) if node.left: stack.append(node.left) return False

[@LemesaElias]

I like how you approach problems and how you don't use some weird built-in functions. Everything is clear and understandable.

[@updownftw]

Hi Greg, what App are you using for Drawing ?

[@jacky-L-327]

what’s the m + n solution

[@GregHogg]

You can read about it in the leetcode editorial section, it's kinda weird

[@aly7401]

Thank you for your tree-based problems video 🎉

[@saideep7510]

@@GregHogg But would this (m*n) solution be good enough for faang interview or would we be expected to know (m+n) solution as well?

[@youngbaron1504]

@@saideep7510i think m+n is very advanced

[@piglovesasy]

this does not feel like an easy problem, more like a medium

[@praneetkomandur6576]

do we need to really know about the time complexity of every leetcode problem we solve

[@GregHogg]

Yes