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construct-binary-search-tree-from-preorder-traversal
Explaining the O(N) approach with C++ code. Beats 100% solutions.
explaining-the-on-approach-with-c-code-b-6fy6
The O(NlogN) approch which everybody tries is O(N\*N). Lets say the case where array is sorted in decreasing order, there it will go quadratic. 5, 4, 3, 2, 1\n\
mehul_02
NORMAL
2020-04-20T08:04:18.832794+00:00
2020-04-20T08:04:18.832830+00:00
7,816
false
The O(NlogN) approch which everybody tries is O(N\\*N). Lets say the case where array is sorted in decreasing order, there it will go quadratic. 5, 4, 3, 2, 1\n\nWe understand the given O(N) solution by:\n1. It is preorder traversal that is all the nodes in left tree is encountered before the nodes of right so we can g...
71
3
[]
12
construct-binary-search-tree-from-preorder-traversal
simple recusrsive cpp solution
simple-recusrsive-cpp-solution-by-bitris-enkl
\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n if(preorder.size()==0)\n return NULL;\n TreeNode*
bitrish
NORMAL
2020-09-10T09:38:45.269172+00:00
2020-09-10T09:38:45.269203+00:00
5,662
false
```\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n if(preorder.size()==0)\n return NULL;\n TreeNode* root=new TreeNode(preorder[0]);\n if(preorder.size()==1)\n return root;\n vector<int>left;\n vector<int>right;\n for(...
59
0
['Recursion', 'C', 'C++']
8
construct-binary-search-tree-from-preorder-traversal
JAVA 3 WAYS TO DO THE PROBLEM! O(N) APPROACH
java-3-ways-to-do-the-problem-on-approac-obh6
THIS IS A CONTINUATION OF MY PREVIOUS POST!\nWHICH HAD O(N^2) APPROACH!\nhttps://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/disc
naturally_aspirated
NORMAL
2020-04-21T03:10:47.892374+00:00
2020-04-21T04:52:52.594307+00:00
6,059
false
THIS IS A CONTINUATION OF MY PREVIOUS POST!\nWHICH HAD O(N^2) APPROACH!\nhttps://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/discuss/589059/java-easiest-solution-with-clear-explanation-of-logic\n\n\nAS A LOT OF PEOPLE ARE ASKING FOR LINEAR SOLUTONS HERE IT IS!\n\nAPPROACH 1-O(N)\nJAVA-LOW...
42
0
['Recursion', 'Iterator', 'Java']
3
construct-binary-search-tree-from-preorder-traversal
C++ Simple and Clean Recursive Solution, Explained
c-simple-and-clean-recursive-solution-ex-udhq
Idea:\nIn a preorder traversal, we visit the root first.\nSo in each iteration, the first element - preorder[i] - is the root\nthen we find the left and right s
yehudisk
NORMAL
2021-10-13T07:31:16.909198+00:00
2021-10-13T07:31:16.909238+00:00
3,632
false
**Idea:**\nIn a preorder traversal, we visit the root first.\nSo in each iteration, the first element - `preorder[i]` - is the root\nthen we find the left and right subtrees and construct the tree recursively.\nIn the left subtree, the maximum value is the current root.\nIn the right subtree, the maximum value is the p...
32
2
['C']
3
construct-binary-search-tree-from-preorder-traversal
Less than 10 lines C++ beats 100%
less-than-10-lines-c-beats-100-by-zhxb51-fhw7
Even though the elements between begin and left are not sorted, we can still apply binary search on it. The reason is that comparing with the value of current r
zhxb515
NORMAL
2019-07-01T23:29:22.915022+00:00
2019-07-01T23:29:22.915065+00:00
2,955
false
Even though the elements between begin and left are not sorted, we can still apply binary search on it. The reason is that comparing with the value of current root element, there is a point that all elements on the left side are smaller than root value, and all elements on the right side are larger.\n\n```\nclass Solut...
30
4
[]
3
construct-binary-search-tree-from-preorder-traversal
[Python] two O(n) solutions, explained
python-two-on-solutions-explained-by-dba-o5el
We can do in simple way: find index for left part, and for right part and do recursion with time complexity O(n^2) for skewed trees and average O(n log n). Ther
dbabichev
NORMAL
2021-10-13T07:32:40.122410+00:00
2021-10-13T07:32:40.122465+00:00
1,389
false
We can do in simple way: find index for left part, and for right part and do recursion with time complexity `O(n^2)` for skewed trees and average `O(n log n)`. There is smarter solution with `O(n)` time complexity, where we give the function a `bound` (or two bounds - up and down) the maximum number it will handle.\nTh...
28
3
['Recursion']
0
construct-binary-search-tree-from-preorder-traversal
JAVA | Clean Code Solution | O(N log N) Time Complexity | 0 ms time
java-clean-code-solution-on-log-n-time-c-y5cl
class Solution {\n \n\tprivate TreeNode insert(TreeNode root, int val) {\n\t\t\n\t\tif(root == null) return new TreeNode(val);\n\t\telse if(root.val > val) root
anii_agrawal
NORMAL
2020-05-24T21:24:32.863828+00:00
2020-05-25T04:36:16.887071+00:00
1,581
false
class Solution {\n \n\tprivate TreeNode insert(TreeNode root, int val) {\n\t\t\n\t\tif(root == null) return new TreeNode(val);\n\t\telse if(root.val > val) root.left = insert(root.left, val);\n\t\telse root.right = insert(root.right, val);\n\t\treturn root;\n\t}\n \n\tpublic TreeNode bstFromPreorder(int[] preorder) { \...
27
2
[]
3
construct-binary-search-tree-from-preorder-traversal
Morris' algorithm (O(n) time / O(n) space)
morris-algorithm-on-time-on-space-by-_ma-0l8l
Hi there!\nI have just solved that problem and started searching for the other solutions that might interest me. However, all users are solving it with the help
_maximus_
NORMAL
2020-04-20T13:58:42.421589+00:00
2020-05-25T10:49:57.425036+00:00
2,720
false
Hi there!\nI have just solved that problem and started searching for the other solutions that might interest me. However, all users are solving it with the help of recursion or stack, and please do not get me wrong those are great solutions, I suggest you try Morris\' algorithm.\n\n**Explanation:**\nThat algorithm diff...
27
1
['Python3']
8
construct-binary-search-tree-from-preorder-traversal
C++ iterative O(n) solution using decreasing stack
c-iterative-on-solution-using-decreasing-lc1i
iterate the input array\nfor each number x, we need to find the first number p less than x from the beginning of the array\nx should be the right child of p\nth
lc19890306
NORMAL
2019-03-10T15:02:01.616218+00:00
2019-09-02T04:40:30.465780+00:00
3,024
false
iterate the input array\nfor each number x, we need to find the first number p less than x from the beginning of the array\nx should be the right child of p\nthus, we need to maintain a decreasing stack\nfor each number x in the array, we try to find the first number p less than x in the stack and make x the right chil...
25
1
[]
5
construct-binary-search-tree-from-preorder-traversal
[C++] Straightforward iterative approach (100%/100%)
c-straightforward-iterative-approach-100-zjmw
Here is my iterative approach to solving the problem. I hope this helps!\n\n\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\
jessephams
NORMAL
2019-04-11T16:58:35.790606+00:00
2019-04-11T16:58:35.790700+00:00
3,145
false
Here is my iterative approach to solving the problem. I hope this helps!\n\n```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode(int x) : val(x), left(NULL), right(NULL) {}\n * };\n */\nclass Solution {\npublic:\n Tre...
22
2
['C', 'Iterator', 'C++']
4
construct-binary-search-tree-from-preorder-traversal
C++ || O(n) || New Approach || No need to figure out Upper Bound or Max_Val
c-on-new-approach-no-need-to-figure-out-sxcpu
OBSERVATION :\nFor any Tree, the Preorder traversal is of this type : \n| root | left subtree | right subtree |\n\nSo, if we are able to identify the index of e
hritesh_bhardwaj
NORMAL
2022-01-24T09:13:01.941753+00:00
2022-01-24T09:19:44.851896+00:00
2,011
false
**OBSERVATION :**\nFor any Tree, the Preorder traversal is of this type : \n| root | left subtree | right subtree |\n\nSo, if we are able to identify the index of ending of left subtree in the given vector preorder.\nThen, we can easily defferentiate the left subtree part with the right subtree part and build the rest ...
19
0
['Tree', 'Depth-First Search', 'Recursion', 'C', 'Binary Tree', 'C++']
4
construct-binary-search-tree-from-preorder-traversal
python beat 100%
python-beat-100-by-jason003-qr05
python\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if not preorder: return None\n root = TreeNode(preorder
jason003
NORMAL
2019-03-23T12:23:26.430229+00:00
2019-03-23T12:23:26.430284+00:00
2,200
false
```python\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if not preorder: return None\n root = TreeNode(preorder[0])\n i = 1\n while i < len(preorder):\n if preorder[i] < preorder[0]: i += 1\n else: break\n root.left = self.bs...
19
2
[]
5
construct-binary-search-tree-from-preorder-traversal
Video solution | Intuition and Approach | Detailed explanation | 🔥🔥🔥
video-solution-intuition-and-approach-de-1sja
Video \nhey everyone, i have created a video solution for this problem and tried to explain this very intuitively, this video is part of trees playlist.\n\nVide
_code_concepts_
NORMAL
2024-08-14T11:38:43.380618+00:00
2024-08-14T11:38:43.380650+00:00
1,711
false
# Video \nhey everyone, i have created a video solution for this problem and tried to explain this very intuitively, this video is part of trees playlist.\n\nVideo link: https://youtu.be/jOLLblvmQA0\nPlaylist link: https://www.youtube.com/playlist?list=PLICVjZ3X1Aca0TjUTcsD7mobU001CE7GL\n# Code\n```\n/**\n * Definition...
18
0
['C++']
1
construct-binary-search-tree-from-preorder-traversal
A Morris Stype method + summary of 4 methods
a-morris-stype-method-summary-of-4-metho-clue
1 morris algorithm\n\n\nThis is in essence similar to the stack solution below, but use the dictionary to eliminate stack. The idea just came to me and I think
newruanxy
NORMAL
2020-05-24T08:21:15.261598+00:00
2020-05-24T08:22:25.936544+00:00
1,757
false
# 1 morris algorithm\n![image](https://assets.leetcode.com/users/newruanxy/image_1590308042.png)\n\nThis is in essence similar to the stack solution below, but use the dictionary to eliminate stack. The idea just came to me and I think the inspiration came from morris algorithm.\n\n```python\ndef bstFromPreorder(self, ...
18
0
['Python']
2
construct-binary-search-tree-from-preorder-traversal
JavaScript solution inspired by lee215 with explanation, O(n) time, O(h) space.
javascript-solution-inspired-by-lee215-w-p7f5
Solution Explanation\n\nThis solution is inspired by this post written by lee215.\n\nThe main takeaway points in this solutions are:\n\n1. Every node has an upp
ecgan
NORMAL
2020-04-20T17:00:44.913446+00:00
2020-04-20T17:00:44.913499+00:00
1,684
false
## Solution Explanation\n\nThis solution is inspired by [this post](https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/discuss/252232/JavaC%2B%2BPython-O(N)-Solution) written by [lee215](https://leetcode.com/lee215/).\n\nThe main takeaway points in this solutions are:\n\n1. Every node ha...
18
0
['JavaScript']
2
construct-binary-search-tree-from-preorder-traversal
c++ Easy straight forward O(N) recursive code
c-easy-straight-forward-on-recursive-cod-vxwa
\n TreeNode* bstFromPreorder1(vector<int>& preorder) {\n int pos =0;\n return bst(preorder, pos, INT_MAX, INT_MIN); \n }\n \n TreeNode
elbanna25
NORMAL
2020-05-17T16:21:12.580471+00:00
2020-05-17T16:23:44.958439+00:00
1,758
false
```\n TreeNode* bstFromPreorder1(vector<int>& preorder) {\n int pos =0;\n return bst(preorder, pos, INT_MAX, INT_MIN); \n }\n \n TreeNode*bst(vector<int>&preorder, int &pos, int max, int min){\n if (pos>=preorder.size()) return NULL;\n int val = preorder[pos];\n if (val > ...
13
1
['C', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
Java: Simple solution to place the nodes to tree one-by-one (100%/100%)
java-simple-solution-to-place-the-nodes-eqs3m
\nclass Solution {\n \n public void addToTree(TreeNode n, int val) {\n if (val < n.val) {\n if (n.left == null) {\n n.lef
mlalma
NORMAL
2019-11-19T12:00:05.716680+00:00
2019-11-24T13:33:23.990753+00:00
1,249
false
```\nclass Solution {\n \n public void addToTree(TreeNode n, int val) {\n if (val < n.val) {\n if (n.left == null) {\n n.left = new TreeNode(val); \n } else {\n addToTree(n.left, val);\n }\n } else {\n if (n.rig...
13
0
['Java']
1
construct-binary-search-tree-from-preorder-traversal
Python 1-liner
python-1-liner-by-ekovalyov-tds5
\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if preorder:\n return TreeNode(preorder[0],\n
ekovalyov
NORMAL
2020-05-24T12:00:31.765757+00:00
2020-05-24T12:00:31.765791+00:00
925
false
```\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if preorder:\n return TreeNode(preorder[0],\n self.bstFromPreorder(tuple(takewhile(lambda x:x<preorder[0], preorder[1:]))),\n self.bstFromPreorder(tuple(dropwhi...
12
0
[]
4
construct-binary-search-tree-from-preorder-traversal
[C++] 0ms Concise Solution | Beats 100% Time
c-0ms-concise-solution-beats-100-time-by-dqzu
\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n if(preorder.size() == 0) return NULL;\n TreeNode* root = NULL;\n for(int i : pre
sherlasd
NORMAL
2020-04-21T06:58:56.332713+00:00
2020-04-21T07:01:39.735931+00:00
889
false
```\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n if(preorder.size() == 0) return NULL;\n TreeNode* root = NULL;\n for(int i : preorder)\n root = InsertBst(root, i);\n return root;\n }\n \n TreeNode* InsertBst(TreeNode* root, int i){\n if(!root) return ...
12
0
['C', 'C++']
3
construct-binary-search-tree-from-preorder-traversal
JAVA 100% FASTER SOLUTION🤯🤯|| RECURSION🙂
java-100-faster-solution-recursion-by-ab-rjx7
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time
abhiyadav05
NORMAL
2023-04-17T14:04:43.600428+00:00
2023-04-17T14:04:43.600460+00:00
1,706
false
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->O(N)\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$...
11
0
['Tree', 'Binary Search Tree', 'Binary Tree', 'Java']
0
construct-binary-search-tree-from-preorder-traversal
javascript, simple recursive
javascript-simple-recursive-by-carti-qjwn
\n/**\n * @param {number[]} preorder\n * @return {TreeNode}\n */\nconst bstFromPreorder = (preorder) => {\n // base cases\n if (preorder.length === 0) return
carti
NORMAL
2020-04-12T00:53:44.118488+00:00
2020-04-22T01:01:40.981315+00:00
1,072
false
```\n/**\n * @param {number[]} preorder\n * @return {TreeNode}\n */\nconst bstFromPreorder = (preorder) => {\n // base cases\n if (preorder.length === 0) return null;\n if (preorder.length === 1) return new TreeNode(preorder[0]);\n\n // result tree node\n var res = new TreeNode(preorder[0]);\n\n // iterate from 1...
11
0
['Recursion', 'JavaScript']
3
construct-binary-search-tree-from-preorder-traversal
💡JavaScript Solution
javascript-solution-by-aminick-5mlf
The idea\n1. Utilize the BST\u2018s peculiarity, which is nodes in the left subtree is smaller than the root, and nodes in the right subtree is bigger than the
aminick
NORMAL
2020-01-31T11:39:53.808923+00:00
2020-01-31T11:39:53.809019+00:00
1,077
false
### The idea\n1. Utilize the BST\u2018s peculiarity, which is nodes in the left subtree is smaller than the root, and nodes in the right subtree is bigger than the root. Use this as a constraint, we can identify subtrees within the preorder array.\n```\n/**\n * @param {number[]} preorder\n * @return {TreeNode}\n */\nva...
11
0
['JavaScript']
0
construct-binary-search-tree-from-preorder-traversal
Simple java solution
simple-java-solution-by-traychev-o3g8
\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root = new TreeNode(preorder[0]);\n for (int i = 1; i < preor
traychev
NORMAL
2019-03-31T12:27:50.552342+00:00
2019-03-31T12:27:50.552371+00:00
2,439
false
```\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root = new TreeNode(preorder[0]);\n for (int i = 1; i < preorder.length; i++) {\n insertIntoBSThelper(root, preorder[i]);\n }\n return root;\n }\n \n public static void insertIntoBSThe...
11
1
[]
3
construct-binary-search-tree-from-preorder-traversal
C++ || pre-order style insertion || iterative || beats 100% / 90.22%
c-pre-order-style-insertion-iterative-be-7qix
This is an amazing solution involving stacks. \n\nAlgorithm:\n\n1) 1st create the 1st element as root and assign an iterator p to it.\n2) Traverse the preorder
sherwin31
NORMAL
2021-05-03T20:24:20.901616+00:00
2021-05-03T20:29:34.915237+00:00
681
false
This is an amazing solution involving stacks. \n\nAlgorithm:\n\n1) 1st create the 1st element as root and assign an iterator p to it.\n2) Traverse the preorder array from index 1 to preorder.size() - 1 (as you\'ve already created 1 node).\n3) Now if the preorder[i] is smaller than p->val, it means this node will lie to...
10
0
['Stack', 'C', 'Iterator']
2
construct-binary-search-tree-from-preorder-traversal
🌺22. Recursive [DFS] || Without Stack || No Extra Space || Short & Sweet Code || C++ Code Reference
22-recursive-dfs-without-stack-no-extra-4u2e0
Intuition\n1. All Elements in Left Subtree Should Be Smaller Than ROOT\n2. All Elements in Right Subtree Should Be Greater Than ROOT\n\n\n# Approach\n- Traverse
Amanzm00
NORMAL
2024-07-09T03:29:20.308456+00:00
2024-07-09T03:32:26.782036+00:00
673
false
# Intuition\n1. All Elements in Left Subtree Should Be Smaller Than ROOT\n2. All Elements in Right Subtree Should Be Greater Than ROOT\n\n\n# Approach\n- Traverse Pre Order Wise \n1. We keep Track Of Bound , Which Is Upper Bound \n2. Elem. Should be Less Than Upper Bound\n\n# Code\n```cpp [There You GO !!]\n\nclass Sol...
9
0
['Array', 'Stack', 'Tree', 'Binary Search Tree', 'Recursion', 'Monotonic Stack', 'Binary Tree', 'C++']
1
construct-binary-search-tree-from-preorder-traversal
✅100% Accepted || Worst to Best approaches with explanation || Easy to understand.
100-accepted-worst-to-best-approaches-wi-fx81
Read the below approaches to understand the logic.\n\nPlease upvote if you like it\n\nApproach 1 : Create tree from given elements approach(Not optimised)\n Fir
pranjal9424
NORMAL
2022-10-02T09:32:58.848569+00:00
2022-10-02T09:32:58.848628+00:00
1,294
false
**Read the below approaches to understand the logic.**\n\n***Please upvote if you like it***\n\n**Approach 1 : Create tree from given elements approach(Not optimised)**\n* First approach could be just create build tree fucntion pass preorder elements one by one and set new node at correct possition by just passing tree...
9
0
['Binary Search Tree', 'Recursion', 'C', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
O(n) recursive solution
on-recursive-solution-by-pratham7711-57fx
\nclass Solution {\npublic:\n \n TreeNode* bstFromPreorder(vector<int>& preorder) {\n return build(preorder,0,preorder.size() - 1);\n }\n
pratham7711
NORMAL
2021-10-13T19:46:24.390597+00:00
2021-10-13T19:46:24.390626+00:00
182
false
```\nclass Solution {\npublic:\n \n TreeNode* bstFromPreorder(vector<int>& preorder) {\n return build(preorder,0,preorder.size() - 1);\n }\n \n TreeNode* build(vector<int> preorder , int start , int end)\n {\n if(start > end)\n return NULL;\n \n \n ...
8
0
['Binary Tree']
0
construct-binary-search-tree-from-preorder-traversal
✅✅ 2 METHODS || BEATS 100% || C++ CODE ✅✅
2-methods-beats-100-c-code-by-neelam_bin-k7tk
METHOD 1:IntuitionWe can build the binary search tree (BST) by following the properties of BSTs and recursively constructing subtrees based on bounds derived fr
neelam_bind
NORMAL
2025-01-06T19:45:05.908274+00:00
2025-01-06T19:45:05.908274+00:00
1,013
false
# METHOD 1: # Intuition We can build the binary search tree (BST) by following the properties of BSTs and recursively constructing subtrees based on bounds derived from the preorder traversal. # Approach 1. Use preorder traversal to process each node. 2. Recursively build the left and right subtrees by updating bounds...
7
0
['Binary Search Tree', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
✅💯🔥Simple Code🚀📌|| 🔥✔️Easy to understand🎯 || 🎓🧠Beats 100%🔥|| Beginner friendly💀💯
simple-code-easy-to-understand-beats-100-hf8f
Solution tuntun mosi ki photo ke baad hai. Scroll Down\n\n\n# Code\njava []\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int
atishayj4in
NORMAL
2024-08-20T21:01:21.206117+00:00
2024-08-20T21:01:21.206139+00:00
858
false
Solution tuntun mosi ki photo ke baad hai. Scroll Down\n![fd9d3417-20fb-4e19-98fa-3dd39eeedf43_1723794694.932518.png](https://assets.leetcode.com/users/images/a492c0ef-bde0-4447-81e6-2ded326cd877_1724187540.6168394.png)\n\n# Code\n```java []\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * ...
7
0
['Array', 'Stack', 'Tree', 'Binary Search Tree', 'Monotonic Stack', 'Binary Tree', 'Python', 'C++', 'Java', 'JavaScript']
1
construct-binary-search-tree-from-preorder-traversal
💯🔥✅Python Simple solution | explained properly
python-simple-solution-explained-properl-x1md
Solution Explanation for Constructing a BST from Preorder Traversal \uD83C\uDF33\n\nIn this solution, we aim to construct a binary search tree (BST) from a give
sagarsaini_
NORMAL
2024-07-26T05:11:03.203351+00:00
2024-07-26T05:11:03.203376+00:00
457
false
## Solution Explanation for Constructing a BST from Preorder Traversal \uD83C\uDF33\n\nIn this solution, we aim to construct a binary search tree (BST) from a given preorder traversal list. The key insight is that in a preorder traversal, the first element is always the root of the tree (or subtree), and the subsequent...
7
0
['Array', 'Binary Search Tree', 'Binary Tree', 'Python3']
0
construct-binary-search-tree-from-preorder-traversal
Brute - Better - Optimal [For Interview] 📄✅
brute-better-optimal-for-interview-by-de-y7w1
\nclass Solution {\npublic:\n \n// BRUTE [T(O(N*N))] [S(O(1))]\n \n TreeNode* insertNode(TreeNode* root,int key)\n {\n if(!root) return new T
debugagrawal
NORMAL
2022-01-14T07:37:20.872398+00:00
2022-01-21T04:59:40.403194+00:00
407
false
```\nclass Solution {\npublic:\n \n// BRUTE [T(O(N*N))] [S(O(1))]\n \n TreeNode* insertNode(TreeNode* root,int key)\n {\n if(!root) return new TreeNode(key);\n if(key>root->val) root->right=insertNode(root->right,key);\n else root->left=insertNode(root->left,key);\n return r...
7
0
['Tree', 'Recursion', 'C']
2
construct-binary-search-tree-from-preorder-traversal
Java monotonic stack solution (Converting Medium to Easy problem)
java-monotonic-stack-solution-converting-z6p0
Below solution uses monotonic stack technique.\n\n Inserting Left node: If the current node is smaller than the node in top of the stack, then it is guarenteed
anirudhbm11
NORMAL
2021-11-19T06:12:04.458097+00:00
2021-11-19T06:12:04.458131+00:00
531
false
Below solution uses monotonic stack technique.\n\n* *Inserting Left node*: If the current node is smaller than the node in top of the stack, then it is guarenteed that node lies in left half of BST.\n* *Inserting Right node*: It gets little tricky in this situtation but if you are aware of the monotonic stack concept...
7
0
['Monotonic Stack', 'Java']
2
construct-binary-search-tree-from-preorder-traversal
Clean Python recursion + binary search solution w/ explanation beats 87%
clean-python-recursion-binary-search-sol-d7en
Recursion solution\n\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if not preorder:\n return None\n
chiou
NORMAL
2020-05-24T07:53:38.790021+00:00
2020-05-24T07:58:06.941234+00:00
704
false
Recursion solution\n```\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if not preorder:\n return None\n root = TreeNode(preorder[0])\n if len(preorder) == 1:\n return root\n\n\t\t# binary search to find the start of right subtree\n l...
7
1
['Python']
0
construct-binary-search-tree-from-preorder-traversal
Simple Java solution
simple-java-solution-by-susmitasingh09-jkzz
\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n int n = preorder.length;\n if (n == 0) return null;\n TreeNode
susmitasingh09
NORMAL
2020-04-20T11:39:01.034084+00:00
2020-04-20T11:39:01.034133+00:00
718
false
```\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n int n = preorder.length;\n if (n == 0) return null;\n TreeNode res = new TreeNode(preorder[0]);\n \n for (int i = 1; i < n; i++) {\n res = insert(res, preorder[i]);\n }\n return res...
7
0
[]
2
construct-binary-search-tree-from-preorder-traversal
Python easy to understand 96% faster (iterative)
python-easy-to-understand-96-faster-iter-5rhg
\n# Definition for a binary tree node.\n# class TreeNode:\n# def __init__(self, x):\n# self.val = x\n# self.left = None\n# self.righ
pujanm
NORMAL
2020-04-20T07:57:46.668039+00:00
2020-04-20T18:07:38.177821+00:00
2,393
false
```\n# Definition for a binary tree node.\n# class TreeNode:\n# def __init__(self, x):\n# self.val = x\n# self.left = None\n# self.right = None\n\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n if len(preorder) == 0:\n return\n \n ...
7
0
['Binary Search', 'Tree', 'Python', 'Python3']
3
construct-binary-search-tree-from-preorder-traversal
6 lines Javascript solution
6-lines-javascript-solution-by-dnshi-8fiy
javascript\n/**\n * Definition for a binary tree node.\n * function TreeNode(val) {\n * this.val = val;\n * this.left = this.right = null;\n * }\n */\n/
dnshi
NORMAL
2019-06-30T00:06:17.617133+00:00
2019-06-30T00:06:17.617216+00:00
711
false
```javascript\n/**\n * Definition for a binary tree node.\n * function TreeNode(val) {\n * this.val = val;\n * this.left = this.right = null;\n * }\n */\n/**\n * @param {number[]} preorder\n * @return {TreeNode}\n */\nvar bstFromPreorder = function(preorder) {\n if (!preorder.length) return null\n \n c...
7
1
['JavaScript']
4
construct-binary-search-tree-from-preorder-traversal
[C++] Easy to understand Solution with detail approach
c-easy-to-understand-solution-with-detai-acxv
Intuition\nThe problem requires constructing a binary search tree (BST) from a given preorder traversal of its nodes. The code uses a recursive approach to buil
Aditya00
NORMAL
2023-05-29T10:06:47.695501+00:00
2023-05-29T10:08:30.452287+00:00
2,165
false
# Intuition\nThe problem requires constructing a binary search tree (BST) from a given preorder traversal of its nodes. The code uses a recursive approach to build the BST by dividing the problem into smaller subproblems.\n\n# Approach\n1. The bstFromPreorder function takes the given preorder traversal as input.\n2. It...
6
0
['Graph', 'Binary Search Tree', 'Recursion', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
C++ | 100% faster | O(n) recursive solution
c-100-faster-on-recursive-solution-by-am-ecm5
\n TreeNode* build(vector<int> pre, int s, int e){\n if(s>e) return NULL;\n TreeNode* root = new TreeNode(pre[s]);\n int idx;\n for(int i=s+1; i<=e
ama29n
NORMAL
2021-10-13T19:12:30.740224+00:00
2021-10-13T19:12:30.740255+00:00
135
false
```\n TreeNode* build(vector<int> pre, int s, int e){\n if(s>e) return NULL;\n TreeNode* root = new TreeNode(pre[s]);\n int idx;\n for(int i=s+1; i<=e; i++){\n if(pre[i]>pre[s]){\n idx = i;\n break; }\n\t}\n root->left = build(pre, s+1, idx-1);\n root->right = build(pre, idx, e);\n...
6
2
[]
0
construct-binary-search-tree-from-preorder-traversal
Java || Easy Approach with Explanation || Recursive || Postorder
java-easy-approach-with-explanation-recu-5uhv
\nclass Solution \n{\n public TreeNode bstFromPreorder(int[] preorder) \n {\n if(root == null)//base case when we are provide with the null graph \
swapnilGhosh
NORMAL
2021-07-27T06:53:48.437980+00:00
2021-07-27T06:53:48.438006+00:00
636
false
```\nclass Solution \n{\n public TreeNode bstFromPreorder(int[] preorder) \n {\n if(root == null)//base case when we are provide with the null graph \n return null;\n \n return constructBST(preorder, 0, preorder.length-1);//it returns the address of the new root of the BST, with al...
6
0
['Depth-First Search', 'Recursion', 'Java']
0
construct-binary-search-tree-from-preorder-traversal
Easy Recursive solution [C++]
easy-recursive-solution-c-by-harshghlt25-om2w
\nclass Solution {\npublic:\n TreeNode* insert(TreeNode* root, int value)\n {\n if(root==NULL)\n return new TreeNode(value);\n if
harshghlt25
NORMAL
2021-05-11T18:36:09.226027+00:00
2021-05-11T18:36:09.226071+00:00
669
false
```\nclass Solution {\npublic:\n TreeNode* insert(TreeNode* root, int value)\n {\n if(root==NULL)\n return new TreeNode(value);\n if(value<root->val)\n root->left=insert(root->left,value);\n if(value>root->val)\n root->right=insert(root->right,value);\n ...
6
1
['Recursion', 'C', 'C++']
1
construct-binary-search-tree-from-preorder-traversal
Python - Concise Solution
python-concise-solution-by-nuclearoreo-zmmm
You pop the first value in the list and make it into node. Next you split the list of values to less than the node as left and larger than the node has right. C
nuclearoreo
NORMAL
2020-04-20T19:15:47.545337+00:00
2020-04-21T13:15:59.685228+00:00
740
false
You pop the first value in the list and make it into node. Next you split the list of values to less than the node as left and larger than the node has right. Continue on untill there\'s no numbers to use. **Note**, you have to set the `index` variable to the length of the list for the case that there\'s no number larg...
6
0
['Depth-First Search', 'Python']
1
construct-binary-search-tree-from-preorder-traversal
JS easy to read preorder traversal (92%runtime/80%space)
js-easy-to-read-preorder-traversal-92run-ydsm
\nvar bstFromPreorder = function(preorder) {\n let root = new TreeNode(preorder[0])\n for (let i = 1; i < preorder.length; i++) {\n appendToTreeNod
GSWE
NORMAL
2020-04-20T16:02:43.127520+00:00
2020-04-20T16:02:43.127602+00:00
268
false
```\nvar bstFromPreorder = function(preorder) {\n let root = new TreeNode(preorder[0])\n for (let i = 1; i < preorder.length; i++) {\n appendToTreeNode(root, preorder[i])\n }\n return root\n};\n\nfunction appendToTreeNode(root, val) {\n if (val <= root.val) {\n if (root.left) appendToTreeNo...
6
0
[]
1
construct-binary-search-tree-from-preorder-traversal
simple recursive insert in bst in CPP
simple-recursive-insert-in-bst-in-cpp-by-vcnw
\nTreeNode* Insert(TreeNode* root,int data){\n if(root == NULL){\n root = new TreeNode(data);\n }\n else if(root->val > data){\n
gowtham_1
NORMAL
2020-04-20T09:17:01.546968+00:00
2020-04-20T09:17:01.547002+00:00
391
false
```\nTreeNode* Insert(TreeNode* root,int data){\n if(root == NULL){\n root = new TreeNode(data);\n }\n else if(root->val > data){\n root->left = Insert(root->left,data);\n }\n else{\n root->right = Insert(root->right,data);\n }\n return r...
6
0
[]
0
construct-binary-search-tree-from-preorder-traversal
Python O(N) Stack based Solution beat 96%
python-on-stack-based-solution-beat-96-b-uujt
The basic idea is using a Stack to keep values, everytime you meet a new value smaller than the end of the stack, you know this new value should be left node of
tanzhenyu2015
NORMAL
2019-10-18T03:28:10.017197+00:00
2019-10-18T03:29:41.558311+00:00
351
false
The basic idea is using a Stack to keep values, everytime you meet a new value smaller than the end of the stack, you know this new value should be left node of it; Otherwise keep popping the stack until you find the last node whose value is smaller than the new value, you know this new value should be right node of it...
6
0
[]
2
construct-binary-search-tree-from-preorder-traversal
3 BEST C++ solutions || Using INT_MAX, recursive and iterative approach || Beast 100% !!
3-best-c-solutions-using-int_max-recursi-ekjw
Code\n\n// Solution 1 - Using max bound\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& pre) {\n int i = 0;\n return build(
prathams29
NORMAL
2023-08-30T02:18:50.547037+00:00
2023-08-30T02:18:50.547054+00:00
548
false
# Code\n```\n// Solution 1 - Using max bound\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& pre) {\n int i = 0;\n return build(pre, i, INT_MAX);\n }\n\n TreeNode* build(vector<int>& pre, int& i, int bound) {\n if (i == pre.size() || pre[i] > bound) \n return...
5
0
['Array', 'Stack', 'Tree', 'Binary Search Tree', 'Monotonic Stack', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
Superb logic
superb-logic-by-ganjinaveen-27of
\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n inorder=sorted(preorder)\n def build(preorder,inord
GANJINAVEEN
NORMAL
2023-07-11T08:53:40.666442+00:00
2023-07-11T08:53:40.666462+00:00
675
false
```\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n inorder=sorted(preorder)\n def build(preorder,inorder):\n if not preorder or not inorder:\n return \n root=TreeNode(preorder[0])\n mid=inorder.index(preorder[0]...
5
0
['Python', 'Python3']
1
construct-binary-search-tree-from-preorder-traversal
✔ C++ | All Tree Construction based Questions at a single place | 2 Approaches of each
c-all-tree-construction-based-questions-htid1
\n### Table of Content :\n\n Construct BST from Preorder Traversal\n\t Recursive Approach\n\t Iterative Approach using Stack\n Construct BST from Postorder Trav
HustlerNitin
NORMAL
2022-08-30T18:05:24.328527+00:00
2022-08-30T18:43:58.612058+00:00
451
false
***\n### Table of Content :\n***\n* Construct **BST** from **Preorder** Traversal\n\t* Recursive Approach\n\t* Iterative Approach using Stack\n* Construct **BST** from **Postorder** Traversal\n\t* Iterative Approach using Stack\n\t* Recursive ( using sorted Inorder property of BST )\n* Construct **Binary Tree** using *...
5
0
['Stack', 'Binary Search Tree', 'C', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
[Python3] O(n) Time Solution 2 Approaches (using Stack and Sorted Preorder)
python3-on-time-solution-2-approaches-us-cxte
Approach 1 - BST from Preorder and Inorder(Sorted Preorder) arrays\n\n# Definition for a binary tree node.\n# class TreeNode:\n# def __init__(self, val=0, l
SamirPaulb
NORMAL
2022-06-02T14:30:35.089626+00:00
2022-06-02T14:31:14.682379+00:00
812
false
Approach 1 - **BST from Preorder and Inorder(Sorted Preorder) arrays**\n```\n# Definition for a binary tree node.\n# class TreeNode:\n# def __init__(self, val=0, left=None, right=None):\n# self.val = val\n# self.left = left\n# self.right = right\nclass Solution:\n def bstFromPreorder(self...
5
0
['Array', 'Stack', 'Binary Search Tree', 'Sorting', 'Iterator', 'Python', 'Python3']
1
construct-binary-search-tree-from-preorder-traversal
C++ || recursive solution || short and clean!!!
c-recursive-solution-short-and-clean-by-xpka9
\nclass Solution {\npublic:\n TreeNode* builtTree(vector<int>& preorder, int &prevIndex, int &boundaryVal)\n {\n if(prevIndex>=preorder.size() || p
priya_07
NORMAL
2022-02-02T19:00:57.404835+00:00
2022-02-02T19:00:57.404863+00:00
402
false
```\nclass Solution {\npublic:\n TreeNode* builtTree(vector<int>& preorder, int &prevIndex, int &boundaryVal)\n {\n if(prevIndex>=preorder.size() || preorder[prevIndex]>=boundaryVal)\n return NULL;\n TreeNode* root=new TreeNode(preorder[prevIndex]);\n prevIndex++;\n root->le...
5
0
['Binary Search Tree', 'Recursion', 'C', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
0 ms, faster than 100.00% ; 13 MB, less than 90.67% [C++]
0-ms-faster-than-10000-13-mb-less-than-9-orcn
```\n/ first element is always the root. \nIterate over the rest array elements & \nperform bst insertion \ntaking first element as root every time /\n\nclass S
_ak_47
NORMAL
2020-12-05T21:11:25.625842+00:00
2020-12-05T21:11:25.625874+00:00
334
false
```\n/* first element is always the root. \nIterate over the rest array elements & \nperform bst insertion \ntaking first element as root every time */\n\nclass Solution {\nprivate:\n void insert(TreeNode* root,int val){\n TreeNode* ptr=root,*prev=NULL;\n while(ptr){\n if(val<ptr->val){\n ...
5
1
['Binary Search Tree', 'C']
0
construct-binary-search-tree-from-preorder-traversal
Simple C++ solution - Easy to understand
simple-c-solution-easy-to-understand-by-f0dcx
\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0)
sanjay_prabhu
NORMAL
2020-05-24T14:21:54.116838+00:00
2020-05-24T14:21:54.116873+00:00
569
false
```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0), left(nullptr), right(nullptr) {}\n * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n * TreeNode(int x, TreeNode *left, TreeNode *right...
5
0
[]
0
construct-binary-search-tree-from-preorder-traversal
C++ | Recursive 100%
c-recursive-100-by-ruddrd09-l1lk
```\nclass Solution {\npublic:\n TreeNode tree(vector& preorder, int i, int j) {\n if(i > j) {\n return NULL;\n }\n TreeNode
ruddrd09
NORMAL
2020-05-24T07:24:39.064554+00:00
2020-05-24T07:24:39.064611+00:00
553
false
```\nclass Solution {\npublic:\n TreeNode* tree(vector<int>& preorder, int i, int j) {\n if(i > j) {\n return NULL;\n }\n TreeNode* root = new TreeNode(preorder[i]);\n if(i == j) {\n return root;\n }\n int k = i+1;\n while(k <= j) {\n ...
5
1
['C']
0
construct-binary-search-tree-from-preorder-traversal
Python3. Simple, clean and easy to understand solution
python3-simple-clean-and-easy-to-underst-ecas
```\nclass Solution:\n def bstFromPreorder(self, preorder):\n root = None\n \n for e in preorder:\n root = self.insert(root, e)\n
abstractart
NORMAL
2020-04-20T18:40:50.129132+00:00
2020-04-25T16:55:05.147219+00:00
469
false
```\nclass Solution:\n def bstFromPreorder(self, preorder):\n root = None\n \n for e in preorder:\n root = self.insert(root, e)\n \n return root\n\n \n def insert(self, node, val):\n if node is None:\n return TreeNode(val) \n \n if val < node.val:\n ...
5
0
['Python3']
0
construct-binary-search-tree-from-preorder-traversal
Python beats 99%
python-beats-99-by-palash2594-ziiu
\n# Definition for a binary tree node.\n# class TreeNode(object):\n# def __init__(self, x):\n# self.val = x\n# self.left = None\n# s
palash2594
NORMAL
2019-06-20T03:29:12.786157+00:00
2019-06-20T03:29:12.786192+00:00
505
false
```\n# Definition for a binary tree node.\n# class TreeNode(object):\n# def __init__(self, x):\n# self.val = x\n# self.left = None\n# self.right = None\n\nclass Solution(object):\n \n def insert(self, root, val):\n if val <= root.val:\n if root.left != None:\n ...
5
1
[]
2
construct-binary-search-tree-from-preorder-traversal
JS recursive
js-recursive-by-chux0519-0e7o
javascript\nfunction TreeNode(val) {\n this.val = val;\n this.left = this.right = null;\n}\nvar bstFromPreorder = function (preorder) {\n i
chux0519
NORMAL
2019-03-12T11:57:29.889717+00:00
2019-03-12T11:57:29.889758+00:00
338
false
```javascript\nfunction TreeNode(val) {\n this.val = val;\n this.left = this.right = null;\n}\nvar bstFromPreorder = function (preorder) {\n if (preorder.length === 0) return null\n if (preorder.length === 1) return new TreeNode(preorder[0])\n let root = new TreeNode(preorder[0])\n ...
5
0
[]
1
construct-binary-search-tree-from-preorder-traversal
Java/C# Recursive solution beats 100% with clear explanation
javac-recursive-solution-beats-100-with-vxpfx
Thoughts: \nThe input array is the preorder traversal of a BST. \n1.preorder[0] is the root of BST\n2.The sub array from preorder[0] to the first element that i
skrmao
NORMAL
2019-03-10T20:16:02.019867+00:00
2019-03-10T20:16:02.019910+00:00
649
false
Thoughts: \nThe input array is the preorder traversal of a BST. \n1.preorder[0] is the root of BST\n2.The sub array from preorder[0] to the first element that is bigger than preorder[0] is the preorder traversal of the left subtree.\n The sub array from element that is bigger than preorder[0] to the end of the array i...
5
1
['Recursion', 'Java']
2
construct-binary-search-tree-from-preorder-traversal
Optimal Approach| O(N) Space Complexity ⭐| Beats 100%
optimal-approach-on-space-complexity-bea-h0dy
Intuition\nThe problem involves constructing a binary search tree (BST) from its preorder traversal. Preorder traversal visits nodes in the order: root, left su
vaib8557
NORMAL
2024-06-15T00:01:58.880601+00:00
2024-06-15T00:01:58.880620+00:00
959
false
# Intuition\nThe problem involves constructing a binary search tree (BST) from its preorder traversal. Preorder traversal visits nodes in the order: root, left subtree, right subtree. Given this order, we can reconstruct the BST by iteratively creating nodes and ensuring that each node respects the BST properties.\n\n#...
4
0
['C++']
0
construct-binary-search-tree-from-preorder-traversal
C++ | 4 different AC solutions : explained ⭐️
c-4-different-ac-solutions-explained-by-ktgri
Code - 1 : using Next Greater Element Array (NGE)\n- We make an array NGE storing the index of the Next Greater Element of each element in the array, and then s
vanshdhawan60
NORMAL
2023-09-05T22:22:43.998471+00:00
2023-09-05T22:22:43.998498+00:00
172
false
# Code - 1 : using Next Greater Element Array (NGE)\n- We make an array NGE storing the index of the Next Greater Element of each element in the array, and then simply construct our tree in preorder fashion using the indices we obtained through our NGE array.\n- This is because we know that all elements upto Next Great...
4
0
['Array', 'Stack', 'Tree', 'Binary Search Tree', 'Monotonic Stack', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
Simple Recursive C++ O(nlogn) solution
simple-recursive-c-onlogn-solution-by-ia-349s
Complexity Analysis\n- Time complexity:\nO(nlogn) in average case, and O(n^2) in worst case\n\n- Space complexity:\nO(h) in average case, where h = height of BS
iamarunaksha
NORMAL
2023-09-03T13:02:38.246639+00:00
2023-09-03T13:02:38.246661+00:00
245
false
# Complexity Analysis\n- Time complexity:\nO(nlogn) in average case, and O(n$$^2$$) in worst case\n\n- Space complexity:\nO(h) in average case, where h = height of BST\nO(n) in worst case, if its a skew-tree\n\n# Code\n```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNo...
4
0
['Binary Search Tree', 'Recursion', 'Binary Tree', 'C++']
1
construct-binary-search-tree-from-preorder-traversal
Easy C++ Solution ✅ | 2 solution | Optimised and Optimal Solution
easy-c-solution-2-solution-optimised-and-esg9
Intuition\nOptimised -> Inorder Traversal is required along with preOrder to create a unique tree. We can get that after sorting preOrder array.\n\nOptimal -> S
HariBhakt
NORMAL
2023-06-06T17:09:38.126563+00:00
2023-06-06T17:09:38.126600+00:00
538
false
# Intuition\nOptimised -> Inorder Traversal is required along with preOrder to create a unique tree. We can get that after sorting preOrder array.\n\nOptimal -> Since for any BST : [Left < Root < Right ]\nWe just to need keep adding nodes after comparing it with the root and its left and right subtree.\n\n# Approach\nO...
4
0
['Recursion', 'Ordered Map', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
Best O(N) Solution
best-on-solution-by-kumar21ayush03-6avs
Approach 1\nBrute-Force\n\n# Complexity\n- Time complexity:\nO(n^2)\n\n- Space complexity:\nO(1)\n\n# Code\n\n/**\n * Definition for a binary tree node.\n * str
kumar21ayush03
NORMAL
2023-03-09T08:50:26.286703+00:00
2023-03-09T08:50:26.286743+00:00
1,624
false
# Approach 1\nBrute-Force\n\n# Complexity\n- Time complexity:\n$$O(n^2)$$\n\n- Space complexity:\n$$O(1)$$\n\n# Code\n```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0), left(nullptr), right(nullptr) {}\n * ...
4
0
['C++']
0
construct-binary-search-tree-from-preorder-traversal
Simple Approach Beats 100% in TC and 90% in SC. || Easy To Understand .
simple-approach-beats-100-in-tc-and-90-i-74i7
Intuition\nFirst Elementr of PreOrder Traversal Array will be root always.\n\n# Approach\nSimply insert the elemnt of given array by comparing if it is greater
jigs_
NORMAL
2023-03-02T13:38:39.907206+00:00
2023-03-02T13:38:39.907242+00:00
334
false
# Intuition\nFirst Elementr of PreOrder Traversal Array will be root always.\n\n# Approach\nSimply insert the elemnt of given array by comparing if it is greater or not ,\n\n# Complexity\n- Time complexity:\nO(N)\n\n\n\n# Code\n```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * ...
4
0
['C++']
0
construct-binary-search-tree-from-preorder-traversal
1008. Construct Binary Search Tree from Preorder Traversal || most easy sol || java
1008-construct-binary-search-tree-from-p-gpuc
// a very clever solution\n// one loop\n// fx call and check\n// see take an indivisual element and then call the fx for placing it \n// if you like the sol the
harjotse
NORMAL
2022-11-03T18:47:06.478641+00:00
2022-11-03T18:47:06.478678+00:00
715
false
// a very clever solution\n// one loop\n// fx call and check\n// see take an indivisual element and then call the fx for placing it \n// if you like the sol then pls upvote :)\n```\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) \n {\n TreeNode root= new TreeNode(preorder[0]);\n for(int i: p...
4
0
['Binary Search Tree', 'Binary Tree', 'Java']
0
construct-binary-search-tree-from-preorder-traversal
Easy Java Solution | Using Recursion
easy-java-solution-using-recursion-by-pi-y8g1
\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root= new TreeNode( preorder[0] );\n \n for(int i: pre
PiyushParmar_28
NORMAL
2022-10-25T06:25:22.736107+00:00
2022-10-25T06:25:22.736147+00:00
984
false
```\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root= new TreeNode( preorder[0] );\n \n for(int i: preorder){\n createTree(i, root);\n }\n \n return root;\n }\n \n public TreeNode createTree(int i, TreeNode root){\n ...
4
0
['Recursion', 'Java']
0
construct-binary-search-tree-from-preorder-traversal
C++ || BST || 2 METHODS || EASY TO UNDERSATAND || STRIVER METHOD
c-bst-2-methods-easy-to-undersatand-stri-a34j
\n//--------------------------------1ST METHOD-----------------------------------------\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& p
_chintu_bhai
NORMAL
2022-10-18T19:44:10.095757+00:00
2022-10-18T19:44:10.095792+00:00
649
false
```\n//--------------------------------1ST METHOD-----------------------------------------\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n vector<int>inorder=preorder;\n sort(inorder.begin(),inorder.end());\n map<int,int>m;\n for(int i=0;i<inorder.size();...
4
0
['Binary Search Tree', 'C']
0
construct-binary-search-tree-from-preorder-traversal
C++ || Two Different Approach || Optimised Solution with 0ms
c-two-different-approach-optimised-solut-r06j
\nclass Solution {\n \n TreeNode * Solve(vector<int>& preorder, int start ,int end)\n {\n if(start>end)\n return NULL;\n \n
Khwaja_Abdul_Samad
NORMAL
2022-08-17T15:04:17.389040+00:00
2022-08-17T15:04:17.389072+00:00
555
false
```\nclass Solution {\n \n TreeNode * Solve(vector<int>& preorder, int start ,int end)\n {\n if(start>end)\n return NULL;\n \n TreeNode * root = new TreeNode(preorder[start]);\n \n int i = start+1;\n for(; i<=end ; i++)\n {\n if(preorder[st...
4
0
['C', 'Iterator']
0
construct-binary-search-tree-from-preorder-traversal
Python | JUST 6 Line Code | Own Solution | O(N) Time
python-just-6-line-code-own-solution-on-1jbk2
\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n if len(preorder)==0:\n return None\n roo
manjeet13
NORMAL
2022-05-27T18:24:47.761416+00:00
2022-05-27T20:20:12.577335+00:00
412
false
```\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> Optional[TreeNode]:\n if len(preorder)==0:\n return None\n root=TreeNode(preorder[0])\n root.left=self.bstFromPreorder([i for i in preorder if i<root.val])\n root.right=self.bstFromPreorder([i for i in pre...
4
0
['Binary Search Tree', 'Recursion', 'Python']
0
construct-binary-search-tree-from-preorder-traversal
Discussed All Approach in Notes | C++ | JAVA
discussed-all-approach-in-notes-c-java-b-gs0q
Notes Link : https://github.com/rizonkumar/LeetCode-Notes/blob/main/1008.pdf\n\nJava Code\n\n\n\nclass Solution {\n public TreeNode bstFromPreorder(int[] pr
rizon__kumar
NORMAL
2022-04-03T04:29:42.247396+00:00
2022-04-03T04:29:42.247440+00:00
73
false
**Notes Link** : https://github.com/rizonkumar/LeetCode-Notes/blob/main/1008.pdf\n\nJava Code\n\n```\n\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n return bstFromPreorder(preorder, Integer.MAX_VALUE, new int[] {0});\n }\n \n public TreeNode bstFromPreorder(int[] preorder, ...
4
0
['Binary Search Tree']
0
construct-binary-search-tree-from-preorder-traversal
C++ | Easy + Efficient solution O(n) TC.
c-easy-efficient-solution-on-tc-by-jv02-je22
\nclass Solution {\npublic:\n TreeNode* tt(vector<int>& p, int& i, int upperbound){\n if(i==p.size() || p[i]>upperbound) return NULL;\n TreeNod
jv02
NORMAL
2022-03-19T11:05:03.464510+00:00
2022-03-19T11:05:03.464537+00:00
159
false
```\nclass Solution {\npublic:\n TreeNode* tt(vector<int>& p, int& i, int upperbound){\n if(i==p.size() || p[i]>upperbound) return NULL;\n TreeNode* root = new TreeNode(p[i++]);\n root->left = tt(p,i,root->val);\n root->right = tt(p,i,upperbound);\n \n return root;\n ...
4
0
['C']
0
construct-binary-search-tree-from-preorder-traversal
[C++] Recursive and Stack Iterative Solutions
c-recursive-and-stack-iterative-solution-cgpe
Recursive:\n\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& p) {\n int id = 0;\n return build(p, id, INT_MAX);\n }\n
ddliu6
NORMAL
2021-10-13T05:54:59.021445+00:00
2021-10-13T17:20:41.792783+00:00
441
false
Recursive:\n```\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& p) {\n int id = 0;\n return build(p, id, INT_MAX);\n }\n \n TreeNode* build(vector<int>& p, int& id, int limit) {\n if(id == p.size() || p[id] > limit)\n return NULL;\n int val = p[id++...
4
0
[]
0
construct-binary-search-tree-from-preorder-traversal
C++ NO STACK, ONLY RECURSIVE CALLS BEATS 100% RUNTIME AND MEMORY
c-no-stack-only-recursive-calls-beats-10-1dzl
Make a function which will insert your elements from the preorder array into the binary search tree in the predefined form of the binary search tree.\n\n\nclass
messi1711
NORMAL
2021-10-13T02:13:12.041026+00:00
2021-10-13T02:13:12.041076+00:00
435
false
Make a function which will insert your elements from the preorder array into the binary search tree in the predefined form of the binary search tree.\n\n```\nclass Solution {\npublic:\n TreeNode* bstFromPreorder(vector<int>& preorder) {\n TreeNode* root=new TreeNode();\n \n root->val=preorder[0]...
4
0
[]
1
construct-binary-search-tree-from-preorder-traversal
Straightforward recursive solution via Python
straightforward-recursive-solution-via-p-yjon
\n# Definition for a binary tree node.\n# class TreeNode(object):\n# def __init__(self, val=0, left=None, right=None):\n# self.val = val\n#
tinfoilhat0
NORMAL
2021-10-13T00:14:52.744814+00:00
2021-10-13T00:14:52.744846+00:00
399
false
```\n# Definition for a binary tree node.\n# class TreeNode(object):\n# def __init__(self, val=0, left=None, right=None):\n# self.val = val\n# self.left = left\n# self.right = right\nclass Solution(object):\n def bstFromPreorder(self, preorder):\n """\n :type preorder: List[...
4
0
[]
1
construct-binary-search-tree-from-preorder-traversal
0ms | 100 beats | Self - Explanatory | JAVA | Recursion
0ms-100-beats-self-explanatory-java-recu-f34d
self explanatory code,\njust make a node for each element and fit it into BST\n\n\n\n\npublic TreeNode bstFromPreorder(int[] preorder) \n {\n if(preor
rahulgilhotra
NORMAL
2021-08-16T10:52:38.452169+00:00
2021-08-16T10:52:38.452200+00:00
479
false
self explanatory code,\njust make a node for each element and fit it into BST\n\n\n\n```\npublic TreeNode bstFromPreorder(int[] preorder) \n {\n if(preorder.length==0) return null;\n \n TreeNode root = new TreeNode(preorder[0]);\n \n for(int i=1;i<preorder.length;i++)\n {\n ...
4
0
['Recursion', 'Java']
0
construct-binary-search-tree-from-preorder-traversal
Java Easy to understand | beats 100% on runtime | self explanatory
java-easy-to-understand-beats-100-on-run-v7id
```\n/*\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode() {}
Backend_engineer123
NORMAL
2021-06-17T19:31:01.183396+00:00
2021-06-17T19:31:39.170872+00:00
292
false
```\n/**\n * Definition for a binary tree node.\n * public class TreeNode {\n * int val;\n * TreeNode left;\n * TreeNode right;\n * TreeNode() {}\n * TreeNode(int val) { this.val = val; }\n * TreeNode(int val, TreeNode left, TreeNode right) {\n * this.val = val;\n * this.left = l...
4
0
['Java']
1
construct-binary-search-tree-from-preorder-traversal
Python O(N) : Easy Recursive using BST property, min & max
python-on-easy-recursive-using-bst-prope-t8k1
```\nimport math\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n \n def construct(preorder,mn,mx):\n
knz_80
NORMAL
2021-04-22T05:40:06.883474+00:00
2021-04-22T05:40:06.883518+00:00
227
false
```\nimport math\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n \n def construct(preorder,mn,mx):\n if preorder:\n\t\t\t\t# Any node value violates bst property\n if preorder[0]<mn or preorder[0]>mx:\n return None\n ...
4
0
['Python']
0
construct-binary-search-tree-from-preorder-traversal
simple c++ solution | recursive
simple-c-solution-recursive-by-xor09-bqoz
\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0)
xor09
NORMAL
2021-02-17T17:28:39.112626+00:00
2021-02-17T17:28:39.112665+00:00
221
false
```\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode() : val(0), left(nullptr), right(nullptr) {}\n * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}\n * TreeNode(int x, TreeNode *left, TreeNode *right...
4
1
['Recursion', 'C']
1
construct-binary-search-tree-from-preorder-traversal
[C++] 5-line solution Time/Space: O(N)
c-5-line-solution-timespace-on-by-codeda-9zpo
\nclass Solution {\npublic:\n int i = 0;\n TreeNode* bstFromPreorder(vector<int>& pre, int upper=INT_MAX) { \n if(i >= pre.size() || pre[i]
codedayday
NORMAL
2020-05-24T17:33:41.544974+00:00
2020-05-24T17:33:41.545014+00:00
290
false
```\nclass Solution {\npublic:\n int i = 0;\n TreeNode* bstFromPreorder(vector<int>& pre, int upper=INT_MAX) { \n if(i >= pre.size() || pre[i] > upper) return NULL;\n return new TreeNode(pre[i++], bstFromPreorder(pre, pre[i-1]), bstFromPreorder(pre, upper)); \n }\n};\n```
4
0
[]
0
construct-binary-search-tree-from-preorder-traversal
Python. No recursion.
python-no-recursion-by-techrabbit58-rt2w
\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n node_stack = []\n node = root = TreeNode(preorder[0])\n
techrabbit58
NORMAL
2020-05-24T12:03:16.397005+00:00
2020-05-24T12:05:54.384511+00:00
580
false
```\nclass Solution:\n def bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n node_stack = []\n node = root = TreeNode(preorder[0])\n for n in preorder[1:]:\n if n <= node.val:\n node.left = TreeNode(n)\n node_stack.append(node)\n no...
4
0
['Python', 'Python3']
2
construct-binary-search-tree-from-preorder-traversal
Recursive Java Solution
recursive-java-solution-by-ztztzt8888-116w
\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root = new TreeNode(preorder[0]);\n for (int i = 1; i < preor
ztztzt8888
NORMAL
2020-04-24T10:22:08.693935+00:00
2020-04-24T10:22:08.693992+00:00
229
false
```\nclass Solution {\n public TreeNode bstFromPreorder(int[] preorder) {\n TreeNode root = new TreeNode(preorder[0]);\n for (int i = 1; i < preorder.length; i++) {\n helper(root, new TreeNode(preorder[i]));\n }\n return root;\n }\n\n private void helper(TreeNode root, Tr...
4
0
['Binary Search Tree', 'Recursion']
0
construct-binary-search-tree-from-preorder-traversal
C++ BST Insert
c-bst-insert-by-eyan422-puar
C++\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode(int x)
eyan422
NORMAL
2020-04-20T09:05:19.328890+00:00
2020-04-20T09:05:19.328925+00:00
549
false
```C++\n/**\n * Definition for a binary tree node.\n * struct TreeNode {\n * int val;\n * TreeNode *left;\n * TreeNode *right;\n * TreeNode(int x) : val(x), left(NULL), right(NULL) {}\n * };\n */\nclass Solution {\npublic: \n TreeNode* BstInsert(TreeNode*& root, int val){\n if(!root){ \n...
4
0
[]
1
construct-binary-search-tree-from-preorder-traversal
C# code easy to understand
c-code-easy-to-understand-by-fadi17-d62c
\n public TreeNode BstFromPreorder(int[] preorder) {\n if(preorder == null)\n return null;\n // root node will always be first node
fadi17
NORMAL
2019-05-26T10:08:56.956579+00:00
2020-04-21T07:15:17.512533+00:00
287
false
````\n public TreeNode BstFromPreorder(int[] preorder) {\n if(preorder == null)\n return null;\n // root node will always be first node in preorder traversal\n TreeNode root = new TreeNode(preorder[0]);\n \n // If we simply just insert all nodes in array \n // us...
4
0
[]
0
construct-binary-search-tree-from-preorder-traversal
Java O(n) solution with range
java-on-solution-with-range-by-tohrah-isfd
\n\nclass Solution {\n int nodeIdx;\n public TreeNode bstFromPreorder(int[] preorder) {\n if(preorder == null) {\n return null;\n
tohrah
NORMAL
2019-03-13T21:10:48.497013+00:00
2019-03-13T21:10:48.497099+00:00
1,058
false
```\n\nclass Solution {\n int nodeIdx;\n public TreeNode bstFromPreorder(int[] preorder) {\n if(preorder == null) {\n return null;\n }\n nodeIdx = 0;\n return bstHelper(preorder, Integer.MIN_VALUE , Integer.MAX_VALUE);\n }\n private TreeNode bstHelper(int[] preorder, i...
4
0
[]
0
construct-binary-search-tree-from-preorder-traversal
Python O(N) short solution using min, max and deque
python-on-short-solution-using-min-max-a-0o6z
\ndef bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n def bst(pre, min, max):\n node = None\n if pre and min < pre[0] < m
Cubicon
NORMAL
2019-03-10T04:00:50.867431+00:00
2019-03-10T04:00:50.867487+00:00
601
false
```\ndef bstFromPreorder(self, preorder: List[int]) -> TreeNode:\n def bst(pre, min, max):\n node = None\n if pre and min < pre[0] < max:\n node = TreeNode(pre[0])\n pre.popleft()\n node.left = bst(pre, min, node.val)\n node.right ...
4
2
[]
0
construct-binary-search-tree-from-preorder-traversal
100% Acceptance! ✅(0ms) Easy To Understand!✅
100-acceptance-0ms-easy-to-understand-by-ho0a
VELAN.MVelan.MComplexity Time complexity: O(n2)✅ Space complexity:O(n)✅ Code
velan_m_velan
NORMAL
2025-03-29T13:12:55.963631+00:00
2025-03-29T13:12:55.963631+00:00
286
false
# VELAN.M $$Velan.M$$ # Complexity - Time complexity: $$O(n^2)$$✅ <!-- Add your time complexity here, e.g. $$O(n)$$ --> - Space complexity:$$O(n)$$✅ <!-- Add your space complexity here, e.g. $$O(n)$$ --> # Code ```cpp [] class Solution { public: TreeNode* bstFromPreorder(vector<int>& preorder) { if(preorde...
3
0
['Tree', 'Binary Search Tree', 'Binary Tree', 'C++']
0
construct-binary-search-tree-from-preorder-traversal
Construct Binary Search Tree from Preorder Traversal
construct-binary-search-tree-from-preord-ezq1
Complexity Time complexity: O(N) Space complexity: O(N) Code
Ansh1707
NORMAL
2025-03-05T23:33:29.579989+00:00
2025-03-05T23:33:29.579989+00:00
208
false
# Complexity - Time complexity: O(N) <!-- Add your time complexity here, e.g. $$O(n)$$ --> - Space complexity: O(N) <!-- Add your space complexity here, e.g. $$O(n)$$ --> # Code ```python [] # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, val=0, left=None, right=None): # ...
3
0
['Stack', 'Binary Tree', 'Python']
0
construct-binary-search-tree-from-preorder-traversal
Java solution || 0ms || 100%faster
java-solution-0ms-100faster-by-ramsingh2-63lk
IntuitionApproachComplexity Time complexity: Space complexity: Code
Ramsingh27
NORMAL
2025-01-10T07:04:11.149893+00:00
2025-01-10T07:04:11.149893+00:00
352
false
# Intuition <!-- Describe your first thoughts on how to solve this problem. --> # Approach <!-- Describe your approach to solving the problem. --> # Complexity - Time complexity: <!-- Add your time complexity here, e.g. $$O(n)$$ --> - Space complexity: <!-- Add your space complexity here, e.g. $$O(n)$$ --> # Code `...
3
0
['Java']
0
construct-binary-search-tree-from-preorder-traversal
✅✅BEST AND SIMPLE SOLUTION🤩🤩
best-and-simple-solution-by-rishu_raj593-0j74
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time
Rishu_Raj5938
NORMAL
2024-09-12T14:16:27.599082+00:00
2024-09-12T14:16:27.599119+00:00
284
false
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ --...
3
0
['C++']
0
construct-binary-search-tree-from-preorder-traversal
just two recursion thats it
just-two-recursion-thats-it-by-sajal-we4k
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time
Sajal_
NORMAL
2024-03-06T12:06:34.042462+00:00
2024-03-06T12:06:34.042498+00:00
861
false
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ --...
3
0
['Python3']
0
construct-binary-search-tree-from-preorder-traversal
[C++] Solution using STACK . Unique approaching . Clean and Easy for understanding
c-solution-using-stack-unique-approachin-07ws
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time
lshigami
NORMAL
2024-01-13T06:44:46.637299+00:00
2024-01-13T06:44:46.637329+00:00
267
false
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ --...
3
0
['C++']
0
construct-binary-search-tree-from-preorder-traversal
||❤️☑️Best Approach using Range Approach☑️❤️|| Recurssive ||Java||
best-approach-using-range-approach-recur-y1jm
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \nThis program is solve i
kailashsahu07
NORMAL
2023-11-16T19:01:47.941270+00:00
2023-11-16T19:01:47.941300+00:00
302
false
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\nThis program is solve in the approach using some range approach . first we have to find the range of all node using some recurssie approach then create node connect it...
3
0
['Java']
0
construct-binary-search-tree-from-preorder-traversal
Python 3 EASY AND FAST/GOOD MEMORY✅✅✅
python-3-easy-and-fastgood-memory-by-bla-onvu
\n\n# Approach\n Describe your approach to solving the problem. \n1. pick the first item as the root.\n2. get the numbers smaller and bigger.\n3. set bst\'s lef
Little_Tiub
NORMAL
2023-09-05T21:38:39.163534+00:00
2023-09-05T21:38:39.163557+00:00
173
false
\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n1. pick the first item as the root.\n2. get the numbers smaller and bigger.\n3. set `bst`\'s left to (background noise: recursing on `smaller`)\n4. set `bst`\'s left to (background noise: recursing on `bigger`)\n\n# Complexity\n- Time complexity: ...
3
0
['Python3']
0
construct-binary-search-tree-from-preorder-traversal
C++ Solution using 0(N) complexity using only preorder
c-solution-using-0n-complexity-using-onl-krzf
\n\t class Solution {\n\t \n public:\n\t\t\n TreeNode solve(vector &preorder , long mini , long maxi , int &i){\n\t\n if(i>=preorder.size()){\
adityagarg217
NORMAL
2023-06-07T20:13:59.825367+00:00
2023-06-07T20:14:53.177920+00:00
1,361
false
\n\t class Solution {\n\t \n public:\n\t\t\n TreeNode* solve(vector<int> &preorder , long mini , long maxi , int &i){\n\t\n if(i>=preorder.size()){\n return NULL ; \n }\n if(preorder[i] < mini || preorder[i] > maxi ){\n return NULL ;\n }\n TreeNode* ne...
3
0
[]
0
construct-binary-search-tree-from-preorder-traversal
Solution C++ (nlogn) using inorder traversal
solution-c-nlogn-using-inorder-traversal-65ty
\n class Solution {\n\n public:\n \n int posi(vector& inorder , int element , int size){\n\t\n for(int i=0; i preorder,vector\ &inorder
adityagarg217
NORMAL
2023-06-07T20:07:22.666449+00:00
2023-06-08T14:24:52.835634+00:00
2,122
false
\n class Solution {\n\n public:\n \n int posi(vector<int>& inorder , int element , int size){\n\t\n for(int i=0; i<size ; i++){\n if(inorder[i]==element){\n return i;\n }\n }\n return -1 ;\n }\n TreeNode* solve(vector<int> preorder,vector...
3
0
[]
0
first-unique-character-in-a-string
Java 7 lines solution 29ms
java-7-lines-solution-29ms-by-zachc-6fal
Hey guys. My solution is pretty straightforward. It takes O(n) and goes through the string twice:\n1) Get the frequency of each character.\n2) Get the first cha
zachc
NORMAL
2016-08-22T16:53:12.466000+00:00
2018-10-25T04:28:35.438130+00:00
154,107
false
Hey guys. My solution is pretty straightforward. It takes O(n) and goes through the string twice:\n1) Get the frequency of each character.\n2) Get the first character that has a frequency of one.\n\nActually the code below passes all the cases. However, according to @xietao0221, we could change the size of the frequenc...
552
10
[]
127
first-unique-character-in-a-string
C++ 2 solutions
c-2-solutions-by-dr_pro-0fi1
Brute force solution, traverse string s 2 times. First time, store counts of every character into the hash table, second time, find the first character that app
dr_pro
NORMAL
2016-08-22T05:58:06.132000+00:00
2021-11-10T06:12:57.370038+00:00
61,185
false
Brute force solution, traverse string s 2 times. First time, store counts of every character into the hash table, second time, find the first character that appears only once.\n```\nclass Solution {\npublic:\n int firstUniqChar(string s) {\n unordered_map<char, int> m;\n for (char& c : s) {\n ...
243
7
[]
34
first-unique-character-in-a-string
Python 3 lines beats 100% (~ 60ms) !
python-3-lines-beats-100-60ms-by-gregs-3ekj
\n def firstUniqChar(self, s):\n """\n :type s: str\n :rtype: int\n """\n \n letters='abcdefghijklmnopqrstuvwxyz'\n
gregs
NORMAL
2016-10-30T19:07:39.451000+00:00
2018-10-25T00:57:48.893360+00:00
66,085
false
``` \n def firstUniqChar(self, s):\n """\n :type s: str\n :rtype: int\n """\n \n letters='abcdefghijklmnopqrstuvwxyz'\n index=[s.index(l) for l in letters if s.count(l) == 1]\n return min(index) if len(index) > 0 else -1\n```
183
18
[]
37
first-unique-character-in-a-string
JAVA || 100% faster code || Easy Solution with Explanation
java-100-faster-code-easy-solution-with-zlpb4
\tPLEASE UPVOTE IF YOU LIKE.\n\nclass Solution {\n public int firstUniqChar(String s) {\n // Stores lowest index / first index\n int ans = Int
shivrastogi
NORMAL
2022-08-16T02:56:45.670698+00:00
2022-08-16T02:56:45.670726+00:00
34,941
false
\tPLEASE UPVOTE IF YOU LIKE.\n```\nclass Solution {\n public int firstUniqChar(String s) {\n // Stores lowest index / first index\n int ans = Integer.MAX_VALUE;\n // Iterate from a to z which is 26 which makes it constant\n for(char c=\'a\'; c<=\'z\';c++){\n // indexOf will re...
182
3
['Java']
16
first-unique-character-in-a-string
Java One Pass Solution with LinkedHashMap
java-one-pass-solution-with-linkedhashma-88s4
LinkedHashMap will not be the fastest answer for this question because the input characters are just from 'a' to 'z', but in other situations it might be faster
nnnomm
NORMAL
2016-08-24T22:23:13.465000+00:00
2018-10-23T02:49:55.412376+00:00
41,261
false
LinkedHashMap will not be the fastest answer for this question because the input characters are just from 'a' to 'z', but in other situations it might be faster than two pass solutions. I post this just for inspiration.\n```\npublic int firstUniqChar(String s) {\n Map<Character, Integer> map = new LinkedHashMap<...
161
4
[]
37
first-unique-character-in-a-string
JavaScript solution
javascript-solution-by-twjeen-wal3
\n var firstUniqChar = function(s) {\n for(i=0;i<s.length;i++){\n if (s.indexOf(s[i])===s.lastIndexOf(s[i])){\n return i;\n
twjeen
NORMAL
2016-08-23T14:16:39.888000+00:00
2018-10-15T01:45:50.710524+00:00
9,635
false
\n var firstUniqChar = function(s) {\n for(i=0;i<s.length;i++){\n if (s.indexOf(s[i])===s.lastIndexOf(s[i])){\n return i;\n } \n }\n return -1;\n };\n\nOR hash map method\n\n var firstUniqChar = function(s) \n var map=new Map();\n for(i=0;i<s.le...
117
2
[]
15
first-unique-character-in-a-string
✅☑Beats 99% || [C++/Java/Python/JavaScript] || 2 Line Code || EXPLAINED🔥
beats-99-cjavapythonjavascript-2-line-co-pj6a
PLEASE UPVOTE IF IT HELPED\n\n---\n\n\n\n---\n\n# Approaches\n(Also explained in the code)\n\n1. Initialize an unordered map (mp) to store character counts.\n1.
MarkSPhilip31
NORMAL
2024-02-05T01:07:11.909951+00:00
2024-02-05T08:05:18.657905+00:00
29,798
false
# PLEASE UPVOTE IF IT HELPED\n\n---\n\n![Screenshot 2024-02-03 053220.png](https://assets.leetcode.com/users/images/42365587-9251-4034-b2b2-48d70f799a37_1707095168.9245899.png)\n\n---\n\n# Approaches\n(Also explained in the code)\n\n1. Initialize an unordered map (mp) to store character counts.\n1. Iterate through the ...
108
5
['Hash Table', 'String', 'Queue', 'Counting', 'Python', 'C++', 'Java', 'Python3', 'JavaScript']
12