Construct String from Binary Tree - Leetcode 606 - Python 

🚀 neetcode.io/ - 25% OFF LAUNCH SALE Just released the first batch of Advanced Algorithm lessons, along with some other updates. A lot more updates coming soon! 🙂

Thanks for making such amazing and very helpful videos!!

i forgot how much i enjoy these videos.

Wow, you work really hard lately. That's really a great contribution to the society. I started watching your solution last year when there were just a few videos in this channel. Now you really make it to a whole new level. Sadly, I just solved around 150 problems for a whole year.

Please don't stop uploading solutions! You are really awesome!

I've got the Amazon New Grad final tomorrow and I was just about to get to this question from the Amazon tagged list. Neetcode coming in clutch again!

How important are the iterative (stack) versions of these recursive solutions from an interview point of view. Because for most problems, if the recursive approach is easy then figuring out the iterative one is almost medium to hard.

Feeling grateful to listen to your explanations neet

Your videos are the most intutive ones.......... Surviving cp bcoz of you brother, If one day I get into Amazon, I will give u whatever u ask for ❤❤❤❤❤❤❤❤

Thanks for your videos and efforts🙏

Please make similary solution daily for the Leetcode Daily Challenges.. Otherwise i have search all over the youtube for other days.. THanks.

Hey could you upload a video for Gray Code question. ik there are multiple solutions in the net, but i feel like ur explanations reach me better

Thanks for the awesome content

Thanks!

How would a binary tree with no left node be represented in array (the input in this case)?

Hey, what software do you use to draw explanations on your video?

Wow, this was just excellent

I recently gave Amazon SWE intern interview, I was asked to find bottom -right view of a tree, at first it may appear hard, but it was just diagonal order traversal and getting last element from each diagonal.

Thank you

Thanks a lot

I have no idea what you just did, but thank you.

Which app do you use to draw?

Wow, Welcome back.

Super Thanks

Hi Sir, I am waiting for your solution to problem #99, 'Recover Binary Search Tree', and an explanation of Morris Traversal if that is the appropriate approach to solve it.

Good explanation but imo it's not just the problem description that's bad but the problem details themselves. I see no reason why the first example isn't ambiguous. Why should leaving out the empty paranetheses be ok on the right but not on the left? Just bc reading left-to-right is natural? Makes no sense to me. imo the expected output is ambiguous and can stand for both of the given example trees. At least a very imprecise explanation which is obviously a no-go for stuff like this.

string dfs(TreeNode* root){ if(root == NULL) return ""; if(root->left == NULL and root->right == NULL) return to_string(root->val); string temp = to_string(root->val); string l = "(" + dfs(root->left) + ")"; string r = ""; if(root->right){ r = "(" + dfs(root->right) + ")"; } return temp + l + r; } string tree2str(TreeNode* root) { return dfs(root); }

update ur roadmap

How is this considered an easy problem? ahah

Thanks!