DIY: Construct a Binary Tree from Preorder and Inorder Traversal

Solve the interview question "Construct a Binary Tree from Preorder and Inorder Traversal" in this lesson.

Problem statement

Given a preorder and an inorder traversal of a binary tree, your task is to construct and return the binary tree.


The input will be two lists containing the preorder and inorder traversals of the tree:

preorder = [3,9,20,15,7]
inorder = [9,3,15,20,7]


Your program should return the entire tree. For the output, we will be show the levelorder traversal of the tree:


Coding exercise

You need to implement the build_binary_tree function in the skeleton code given below.

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