[LeetCode][Python3] 105. Construct Binary Tree from Preorder and Inorder Traversal

Problem :

https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/

My Solution :

# Definition for a binary tree node.

# class TreeNode:

# def __init__(self, x):

# self.val = x

# self.left = None

# self.right = None

class Solution:

def buildTree(self, preorder: List[int], inorder: List[int]) -> TreeNode:

def build(preorder, inorder, left, right):

if left < right:

root = TreeNode(preorder[self.pre_idx])

root_idx = inorder.index(root.val, left, right)

self.pre_idx += 1

root.left = build(preorder, inorder, left, root_idx)

root.right = build(preorder, inorder, root_idx+1, right)

return root

self.pre_idx = 0

return build(preorder, inorder, 0, len(inorder))