105. Construct Binary Tree from Preorder and Inorder Traversal
Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree.
Example 1:
Input: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7] Output: [3,9,20,null,null,15,7]
Example 2:
Input: preorder = [-1], inorder = [-1] Output: [-1]
Constraints:
1 <= preorder.length <= 3000inorder.length == preorder.length-3000 <= preorder[i], inorder[i] <= 3000preorderandinorderconsist of unique values.- Each value of
inorderalso appears inpreorder. preorderis guaranteed to be the preorder traversal of the tree.inorderis guaranteed to be the inorder traversal of the tree.
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Similar problems
Construct Binary Tree from Inorder and Postorder TraversalMediumLoading editor…
1# Definition for a binary tree node.
2# class TreeNode:
3# def __init__(self, val=0, left=None, right=None):
4# self.val = val
5# self.left = left
6# self.right = right
7class Solution:
8 def buildTree(self, preorder: List[int], inorder: List[int]) -> Optional[TreeNode]:
9
Starter codePython 3Spaces: 4
Loading editor…
1# Definition for a binary tree node.
2# class TreeNode:
3# def __init__(self, val=0, left=None, right=None):
4# self.val = val
5# self.left = left
6# self.right = right
7class Solution:
8 def buildTree(self, preorder: List[int], inorder: List[int]) -> Optional[TreeNode]:
9
Starter codePython 3Spaces: 4
Examples
Input
[3,9,20,15,7] [9,3,15,20,7]
Input
[-1] [-1]
Your code is saved on this device.Solution