Same Tree - Leetcode 100 (Python)

leetcode, coding interview question, data structures, data structures and algorithms, faang

[GregHogg]

Master Data Structures & Algorithms and CRUSH your next Coding Interview for FREE at AlgoMap.io!

[BlissOn]

Bros vocal cords are running a non terminating voice crack loop

[nagyzoli]

you do not need to check separate Null vs not null and value 1 vs value 2. If a != b should capture both cases

[DavideCanton]

This is true if you are checking that the trees have the same structure, but not if you have to check that they have the same values, as BSTs can have different structures with the same values

[lolous-studio]

Convert both to bytes, hash both, check and voilà !

[keyboardbasher]

class Solution:
def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
if p is None or q is None:
return p == q
return (p.val == q.val) and self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

[alexgjeka]

Would a BFS approach to this be better

[EternalCelestialChambers]

Just do preorder traversal of both and compare the results.

[luckytrinh]

I thought you wanted to do graph isomorphism on trees 😢

[Samsung-zgql]

Just to make a catchy acronym "fang", they leave out Microsoft but inlcude Netflix 🤣🤣

[axhraf]

second if statement can be a simple or, because the and has already been checked in the if statement above it 🤓☝️

[airkami]

I wouldn’t copy a tree. Not the answer they want but if the tree is so critical that a copy of it would need to be tested to be 100% sure it wasn’t bad, I would just use the original. If we can’t use the original, then we designed something wrong.

[boyangli]

I think the minimum requirement for this problem should be to not use recursion, otherwise this is nothing special to list comparison.

[bilalraja]

Couldnt you simplify the 2nd if statement to if not p or not q? Since we already return above if both are null. Your 2nd if check is unnecessarily verbose.

[RTU-mwft]

Hi Greg. I wanted to ask as someone who is in last year of college but has never studied graphs or DP properly, Is your youtube playlist and algomap questions enough for these topics? I use Java by the way.

[renzo]

Wouldn't "if not q" return false if q is integer 0?

[eyluismi]

Easier: Its a duplicated binary tree so they should be the same. 😛

[joelbacker]

Let’s all hope that p and q are never 0

[NilAtabey]

why can we not do else return False after #1?

[SabinSipai]

I seriously failed to understand the logic here