Construct Binary Tree from Preorder and Inorder Traversal

arrayhash tabledivide and conquer

Problem Statement

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 .

Examples

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 <= 3000

inorder.length == preorder.length

-3000 <= preorder[i], inorder[i] <= 3000

preorder and inorder consist of unique values.

Each value of inorder also appears in preorder .

preorder is guaranteed to be the preorder traversal of the tree.

inorder is guaranteed to be the inorder traversal of the tree.

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Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table